Dolphin M200 Pool Cleaner VS Dolphin M400 Pool Cleaner

Check mark Highs
2 brushes
Easy-to-clean filter cartridges
Fine and ultra-fine filtration
Workhorse power
Extremely durable
X icon Lows
Hefty
Caddy not included
1 cleaning cycle option
Tracks are loose
Coverage Very Good Good
Filtration Excellent Excellent
Cleaning Excellent Excellent
Intelligence Very Good Fair
Usability Very Good Good
Maintenance Excellent Excellent
Value Very Good Good
Check mark Highs
3-Year Limited Warranty
Easy-to-Clean Filtration System
Underwater Mobility
Extremely Durable
Cleans All the Way to Waterline
X icon Lows
Bluetooth Is Spotty
Remote Control Lags
Lingers on Steps
MyDolphin App Is Unintuitive
Coverage Very Good Good
Filtration Excellent Excellent
Cleaning Excellent Excellent
Intelligence Very Good Fair
Remote Usability Poor
Bluetooth Usability Poor
Maintenance Very Good Good
Value Very Good Good

Head To Head Review Analysis

Is the Dolphin M200 the best robotic pool cleaner on the market? No. But based on its price and performance, it’s the best at what it does. Without unnecessary bells and whistles, the M 200 can devote all of its design and energy into doing the hard work you don’t want to do anymore. It’s a solid climber, scrubs deeply, filters like a champ, and powers through obstacles like a tank. The M200’s performance even outshines its affordability. For all pool owners looking for an economical workhorse to do the dirty work for them, look no further than the M200.


The Dolphin M400 robotic pool cleaner offers top-grade performance at a mid-range price. Many reviewers say they wish it hadn’t taken so long to buy one, and we now see why. Its durability, cleaning efficiency, and ease of ownership all culminate into an outstanding pool cleaner. The very few flaws it has are overshadowed by the burden it consistently lifts off of pool owners’ shoulders. With this machine you can simultaneously get rid of the pool guy and lower your electric bill. The M400 is fully capable of doing the dirty work for you – all at a very reasonable price.


Dolphin M200 Pool Cleaner

Dolphin M400 Pool Cleaner

Customer Reviews

4.4 stars 4.4 Based on 12 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
How would you rate Dolphin M200 Pool Cleaner?*
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4.5 stars 4.5 Based on 63 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
How would you rate Dolphin M400 Pool Cleaner?*
Rating Stars
Rating Stars
5 Stars

Ed Callaway -

It is durable and dependable

Rating Stars
5 Stars

Brittany -

It works amazing

Rating Stars
5 Stars

Holly Mothes -

Love our pool cleaner! Gets the job done.

Rating Stars
I love Dolphin M200

HG -

I love it! I used to clean the pool manually but then I injured my knee and it was hard for me to clean the pool. Dolphin made my life easier and I don’t have to worry about keeping my pool clean. It does a great job and really love it. I will definitely recommend it to family and friends.

Rating Stars
very pleased with my Dolphin M200

Bruce Gramm -

I bought this cleaner 2 years ago. I have been very pleased with how well it cleans the pool. I would definitely reccomend this product to others.

Rating Stars
Great pool cleaner

Mark -

We purchased a Dolphin based on a friends recommendation and are pleased with how clean it keeps the pool. It is impressive how it cleans the water line without falling off the walls. Clean up is easy and quick. No complaints. Looking forward to the Dolphin helping me open the pool in a few weeks.

Rating Stars
Love our Dolphin!

Tammy O”Connor -

I have used the Dolphin M200 for 2 years now and love how well it does and the ease of cleaning the filters. I hope it lasts a long time. We are very happy with it.

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Happy Cleaning

Charlie Smerage -

Works great does a better job on the water line than I expected.

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Greatest tool ever for keeping pool clean and perfect all summer long!

JD Harper -

I love this product. I wish I had know about it sooner! It has absolutely eliminated my need to vacuum our pool…talk about making pool maintenance a breeze, the Dolphin M200 is a winner…and so easy to use…truly plug it in, set the desired cleaning schedule and boom ready to go…cleaning filters is just as easy, remove, hose off and replace…bing, bang boom, you’re done! And, it’s fun and relaxing to watch while operating. I sit on our porch in the mornings while it cleans the pool, enjoying my coffee and watching Sal Stingray…that’s my name for our cleaner because it is so graceful and quiet while it meanders throughout the pool, just like a stingray!

Rating Stars
5 Stars

JR -

Love this pool cleaner. Wish we would have purchased one years ago. Makes opening pool in the spring so much easier!

Rating Stars
Tracks come off

M Longmire -

I am very disappointed in the Maytronics robots. This is the third unit they have provided after 4-5 returns for maintenance because the tracks continue to come off. I have a standard rectangular vinyl inground pool, and have only been using the cleaners for 2 years all combined. I get about 2 cleaning cycles before losing a track. Since I have seen it with multiple units I assume it is a design flaw.

Rating Stars
Very Disappointed

A. Hagedorn -

I bought the dolphin m200 yesterday. I followed the instructions and put it in the pool and plugged it in and pushed start. It seems to be moving well, but it just makes tracks all over my pool. I had already cleaned up all the larger debris, so now it is just dirt. I have tried both sets of filters. For the price, I really had hoped that it would clean really well. I contacted support yesterday, but have not heard anything yet.

Rating Stars
Very Reliable

NIck Jacob -

We have had our unit for 4 years with no problems. My only complaint is that the set of fine filters we bought have come apart from the plastic frame at the bottom. A Friend with the same unit had this problem and she has glued hers together, we need to do the same.

Rating Stars
The Best Robot

Doug Messina -

Did alot of research before purchasing the M400. I previously had an Aquabot T4 which I thought was good, that is until I started using the M400. The M400 performs circles around the Aquabot( which was the best rated and most expensive consumer robot at the time) and addresses the inefficiency of the T4. First, the power cord does not tangle. The interchangeable filtration cartridges collect more debris and are easier to clean. The M400 is much easier to operate and ca be set for up to 3-hours. Does a better job of cleaning walls, however it can’t negotiate steps very well. The only drawback is the weight. It is heavy, especially when removing from the water, however, considering the performance, it is completely acceptable. I am in my second year of operation and would recommend the M400 to everyone who wants the best consumer level robotic pool cleaner available.

Rating Stars
Drop it in and walk away

JMAN54 -

When our in-ground pool was installed, our pool guy included another brand of automatic pool cleaner. It ran one cycle perfectly. The second time I went to use it, it wouldn’t start. WHAT??? Our pool guy replaced it -no questions asked- with a Dolphin M400. Smooth sailing ever since; now in third season. Recommended product.

Rating Stars
M400 Review

Rick Wojan  -

After researching all of the different pool cleaners I bought the M400 and couldn’t be happier – it does a great job of completely cleaning the pool – floor, walls and steps. It’s quite easy to operate and saves me hours of time during the week and on weekends. On top of this their Customer Service is phenomenal and a pleasure to work with – they take the time to call and email back promptly (thanks Mandy and Tamara) to answer a request. Purchase a Dolphin and save yourself time, money and researching other manufacturers as the M400 is top notch in every respect. Then get yourself a proper beverage and watch it work.

Rating Stars
Pac Man

Bill -

We have been using the M400 for more than nine months, and very pleased with it’s performance. The M400 is used on a three day interval…one day on two days off, unless they is allot of wind. The unit is used on a pebble sheen pool surface, and does a quality job, the unit can not maneuver in tight corners, one just needs to be aware of this short coming. The middle roller does an great job on the pool surface. The filters have easy top access, and very easy to clean. The filtration system has extended the pools main filters from three months to a four month , may be a five month clean cycle. A good investment one of my neighbors also purchased a M400 after we used our unit in his pool, which made a significant improvement in the cleanliness in their pool . Maytronics , needs to provide a replacement parts kit to it customer…I see the need to replace the tracks in six to nine months.

Rating Stars
Clean pool

Alan Blatterman -

The Dolphin M4000 is an awesome cleaner. I just drop it into the pool and a few hours later the is clean. Then I take the Dolphin out, clean the filters and put it away. My pool is now very clean. It gets even the smallest sand/dirt particles that were not gotten when I use to clean by hand vacuum.

Rating Stars
Wish I had one sooner

Jr -

Two pools, two M400s. Works great! Beats the Polaris hands down. Get one, you you’ll be glad you did.

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Year 3 and All Is Well

Jim Phalen -

The best pool vacuum cleaner I have owned. Runs circles around those “rubber band” vacuums. Its been a blessing.

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love my Dolphin M400

Thom Manchester -

’ve tried Polaris(horrible),Aquabot (not to bad) but I love the Dolphin M400. The ease of cleaning is the best, just rinse the filter and pop it back in. The unit covers the pool area perfectly. My pool is 16’x36? 10 ft. deep end inground. I like that it climbs the walls. I use to scrub the walls by hand, not anymore.

Rating Stars
Great value

Mike -

Saves time and effort keeps pool clean and works on side of pool. Get value, owned for three seasons without any problems

Rating Stars
Easy to use

Ruben Quintanilla -

I’ve had this unit about a year now. Very easy to use. Cartridges easy to remove and clean. Doesn’t leak debris back into the pool when removing to clean like my last unit. Love the built in timer on the power supply.

Rating Stars
Sure beats Polaris Booster cleaner

Larry Burns -

By far the best cleaner we have ever used, started off with Letro Legend that came with pool, ok but, not great, then purchased Polaris, little better, but not considering a booster pump and motor is used. Enter Dolphin M400, after some consideration and wondering if cleaner worth the price. We quickly got over what seemed like sticker shock when the improvement was evident from the first use. We recommend this unit as we have been well pleased. Thanks Maytronics.

Rating Stars
Hands down the best!!!

Bill -

This cleaner is the best!!!! Owned a Polaris and it did not even come close to the cleaning performance of my dolphin M400. Better versatility, duel types of cleaning and does the job in half the time. I expect it will save a ton in electricity not having to run a booster pump for an inpool cleaner, so add that to the plus’s!!!! Great product and well worth the investment!!!

Rating Stars
M400

Donald Kazawic -

This cleaner is by far the best thing i purchased for our pool. You just place it in and walk away. The pool has stayed cleaned and freed me up to spend more time in the pool. The 3 wheeled vacuum was driving me crazy, always tangled up and never cleaned the pool. My dolphin M400 gets all the fines in the water that you can’t even see. I saw that my local pool store had one to demo and as soon as i tried it for a day i was sold on it.

Rating Stars
M400 overall performance and unfortunate Power cord failure

Richard -

The in-pool M400 is excellent. I have a very unique shaped pool with a 6 ft wide beach approach at a 90 degree angle to the rest of the pool. The M400 does a fantastic job of learning the pool and cleaning it. After 13 months of usage the M400 quit. I took it to the store where I purchased it and they determined the power cord had a manufacturing problem that lead to the failure. They corrected the problem with a complete new cord, at no cost to me, being under Warranty. The cord replacement was going to take 4-5 weeks so they gave me their store demo unit. This kind of service reinforced my decision to buy at a store versus online. I am so pleased. The unit is back and once again working perfectly.

Rating Stars
The BEST

Bret Andrews -

This is the best pool cleaner on the market.

Rating Stars
Excellent robotic vacuum pool cleaner

Leo Neil Ligon -

Reliable and excellent pool vacuum cleaner. This is the first pool vacuum cleaner in our 18x36ft rectangular vinyl liner salt water pool. The cleaning takes 3 hours, about 90% are covered, which is excellent in robotic pool cleaner standards today. Highly recommended pool robotic vacuum cleaner.

Rating Stars
Save Time and Enegry !

Charles -

Excellent product which produces outstanding results. Purchased end of the summer, notice how well it performed, just open pool and it has lived up to its rating. I also own small Aqua King which I use for light cleaning. With all the pollen , I highly recommend the M400, ease of entry, easy to clean filters which is #1 in my mind.

Rating Stars
Love it!

Elizabeth -

It is a bit heavy. It’s not too bad when putting it into the pool But it is particularly heavy when pulling it out of the pool. But it does a wonderful job of cleaning. Our pool has never been this clean. It’s great to be able to turn it on and let it go. And a bit mesmerizing to watch it working!

Rating Stars
Love this little guy!!

Andy -

I LOVE this Dolphin! The M400 is the absolute best investment we have made for our pool! Is it heavy? Maybe, but it is full of water when pulling it out of the pool after all and it is a machine!! Do you have to clean out the filters…well of course you do! I have yet to brush my pool in the two years I have owned our M400 and our 40×18 pool remains crystal clear with zero issues. Our model came with both the paper filters and the mesh filters, you can always buy extras on Amazon if necessary. Wonderful product, perfect with the app so you can control it if needed. There is nothing to complain about with this awesome pool cleaner!

Rating Stars
Best thing ever!!

Cristy -

Made taking care of my pool so easy! No more paying someone to do it and/or accommodating their schedule.

Rating Stars
Phenomenal pool cleaner !

Tony Ciccone -

I purchased the dolphin M 400 swimming pool cleaner for my inground swimming pool and I couldn’t be more happier my pool has never look cleaner it does the walls does the floors it does the steps it’s very easy to use .There is a light that goes on if the cartridges are dirty .to remove the cartridge it takes all of a minute I hose it down put it back in the machine and put it backinto the pool to clean again I have a 16 x 28‘ inground pool and it cleans it in within an hour I couldn’t be more happier I would definitely buy another Dolphin pool cleaner

Rating Stars
my pool boy

Donald Pacheco -

I love my Dolphin I have had other pool cleaners and they don’t last this so far has been going strong I clean it after it does the work and in the winter I clean it and put it in the basement where it does not go below 50 degrees. Hopefully it will last a few years but I would buy another one if the need arises. We have such a short season June to September but I love my little cleaner.

Rating Stars
Hard to express just how GREAT this tool is!

Frank Ruggerie -

Forget the expense of pop-up floor-systems and let this robot loose in your pool. It normally cleans the floors, walls and tile of a 38,000 gallon gunnite pool with contour surfaces in three (3) hours. I have three seasons (around 200 cleanings) on this Dolphin M-400. The power-cord was replaced at no-charge and I purchased a second set of filters. At some point I expect it will need the “rollers” replaced and hope there will be a convenient source to provide that service. So far, this little workhorse has been bulletpro

Rating Stars
Awesome machine

Terry Trent  -

The most bang for the money!!! We have been using the M400 for over a year and it paid for it self quickly and my wife and I just love the way it cleans everything, sides bottom along the waterline it is just awesome . It even filters the water with the paper filters installed !!!

Rating Stars
Love it

Albert St. Pierre -

Does the job as advertised.

Rating Stars
5 Stars

Christy B -

We LOVE our Dolphin, it does a great job of keeping our pool clean. Saves us so much time and work. We have a pebblecrete finish and tile mosaics and it cleans everything, except the top step. We use it almost daily during pool season because we enjoy a clean pool. The old vacuum was a pain with having to first brush down the walls, then drag out the hose, hook it up, and spend all that time and energy hand vacuuming. Now we just put the Dolphin in, push a button and enjoy letting it do all the work. Only regret is we wish we had gotten it sooner.

Rating Stars
Dolphin pool sweep M400

David Jo Ann Haynes -

Wish we purchased sooner. Does a great job

Rating Stars
Excellent Results

Jim -

We have had this now 3 years and no problems. It’s pretty smart, but it rarely misses the debis in the pool. I have the remote which works great. Battery just died last week, but I will replace this week. A nice touch for focusing the unit. It does not pick up the acorns well, but I consider that a very minor issues. The cardboard-type filters are my favorite over the mesh filters that come with the unit. Well worth the extra expense. They have lasted the full 3 years.

Rating Stars
5 stars

Denise Hester -

Great pool vacuum!

Rating Stars
5 Stars

Augie Pellegrini -

Simply awesome how much debris it picks up. Very easy to clean with top loading cartridges. Happy to be done with bag systems. Wish the top doors stayed closed a little tighter.

Rating Stars
a unbelievable product...M400

Richard Rossy -

I purchased my Dolphin M400 in August 11, 2017. My pool is 33 years old and rather large 44×27 feet with a 10 foot deep end. Up until last year, I cleaned my pool manually, always believing that Robotic pool cleaners would never come close to a manual clean, that is a brush attached to a vacuum system. Well I was wrong, my Maytronic M400 is a unbelievable product and happy to say that I have retired from cleaning my pool manually. The M400 does the same job equally as well, maybe better…

Rating Stars
Enjoying our pool time!

Patrick Clynes -

We love our dolphin! Even though we only spend weekends at our house with the pool, cleaning is so easy. We just put in the dolphin on Friday evening and once again on Sunday and it cleans our pool beautifully every time.

Rating Stars
Best purchase ever!

Judy Medvid -

I use to dread summer with all the work of vacuuming my 20×40 pool. Now it’s on automatic pilot with my Dolphin. It keeps the water perfectly clean. Just the way I like it!!

Rating Stars
I'm a big fan of Dolphin Products

Joe Whitbeck -

The M400 does a fantastic job keeping the pool clean and me happy. The worst part of owning a pool is the upkeep. The M400 does the hard work for you – cleaning. Put it in the pool, turn it on the desired duration and sit back and watch it scour the bottom of your pool picking up just about everything it comes near. It’s also easy to clean. The new cartridge systems are a breeze to get out, clean and replace. I won’t own a pool without a Dolphin product swimming at the bottom.

Rating Stars
Almost perfect

Austin Javes -

I haven’t had a bit of trouble with this machine. The only blemish to its operation is that it sometimes doesn’t cover the whole pool and then I have to go to all that trouble of pressing a button again.

Rating Stars
DOLPHIN M400 GREAT TIME SAVER

Ana V Benitez -

Before I bought the Dolphin M400 my husband would spend hours sucking out the dirt in the pool through a hose that hooks up to the skimmer sending the dirt to the filter. Now he just throws the Dolphin M400 in the water and it sucks the dirt into the filters inside the Dolphin M400, hence extending the life of the pool filter and he leaves the Dolphin unattended for whatever time he likes and goes on to do other things or simply have fun watching it.

Rating Stars
The best Robot made.

Al Watson -

I have my Dolphin M400 for three years now. Never had any problems at all. It cleans my pool in about 45 minutes. Just make sure that you clean the filters after every use. Love it.

Rating Stars
Love my Dolphin!

Jimmy -

I have a fiberglass pool and had used an older model that lasted over 8 years.During that time, I never had to manually vacuum my pool. The only issue I had was that it would hang up on the main drain because it only had two brushes. I purchased the M400 because it had a 3 brushes and it never hangs up! I really like the easy clean filters. The only down side of the M400 is the weight. I don’t have an issue getting it out of the pool, but it is a struggle for my wife. I would definitely recommend a Dolphin to anyone look for a great pool cleaner.

Rating Stars
M400

Jim Paliotta -

Love it. Performs very well. Had a pool cleaner that ran through the filter which did not perform as well is the self contained filters and did not go up the side walls.

Rating Stars
Great addition

George Hallas -

Works well and provides more free time

Rating Stars
Very Reliable

NIck Jacob -

We have had our unit for 4 years with no problems. My only complaint is that the set of fine filters we bought have come apart from the plastic frame at the bottom. A Friend with the same unit had this problem and she has glued hers together, we need to do the same.

Rating Stars
The Best Robot

Doug Messina -

Did alot of research before purchasing the M400. I previously had an Aquabot T4 which I thought was good, that is until I started using the M400. The M400 performs circles around the Aquabot( which was the best rated and most expensive consumer robot at the time) and addresses the inefficiency of the T4. First, the power cord does not tangle. The interchangeable filtration cartridges collect more debris and are easier to clean. The M400 is much easier to operate and ca be set for up to 3-hours. Does a better job of cleaning walls, however it can’t negotiate steps very well. The only drawback is the weight. It is heavy, especially when removing from the water, however, considering the performance, it is completely acceptable. I am in my second year of operation and would recommend the M400 to everyone who wants the best consumer level robotic pool cleaner available.

Rating Stars
Drop it in and walk away

JMAN54 -

When our in-ground pool was installed, our pool guy included another brand of automatic pool cleaner. It ran one cycle perfectly. The second time I went to use it, it wouldn’t start. WHAT??? Our pool guy replaced it -no questions asked- with a Dolphin M400. Smooth sailing ever since; now in third season. Recommended product.

Rating Stars
M400 Review

Rick Wojan -

After researching all of the different pool cleaners I bought the M400 and couldn’t be happier – it does a great job of completely cleaning the pool – floor, walls and steps. It’s quite easy to operate and saves me hours of time during the week and on weekends. On top of this their Customer Service is phenomenal and a pleasure to work with – they take the time to call and email back promptly (thanks Mandy and Tamara) to answer a request. Purchase a Dolphin and save yourself time, money and researching other manufacturers as the M400 is top notch in every respect. Then get yourself a proper beverage and watch it work.

Rating Stars
EXCELLENT VACUUMING, but POOR HANDLE SLOT INSTRUCTIONS (after 2 years, still trying to figure it out)

S. A. Martinez -

My “buddy” really takes the cleaning part of the bottom of the pool out of my chores to do, but I didn’t really come across an easy to understand instruction/explanation on how to use the handles and their different available positions……………….

Rating Stars
Dolphin pool cleaner

LRaines -

Works great, not perfect, but certainly easy to use and no labor for me. Sometimes have to run the cleaner 2 cycles if the pool is very dirty. Heavy to lift out of the water but I was expecting that since I had read the reviews. Filters are easy to clean and they really do pick up small particles. No complaints – I’m very happy we purchased this after many years of hand vacuuming, and later using a cleaner that runs off the skimmer . Would advise anyone to buy if they are looking for an automatic cleaner.

Rating Stars
Does a really nice job!

Sue Fraser -

I love the ease and convenience of this robotic cleaner. I used to dread the vacuuming and now I just toss the Dolphin in the pool and let it go. I have an in-ground 18×36, and I typically have to run it twice through to get it fully vacuumed. I do need to manually do the corners of the pool, since the Dolphin never gets those, which it why I gave 4 stars and not 5, but overall it was a good investment and has served me well.

Rating Stars
Quality Time with Friends and Family

Greg Onjack -

I’ve been a pool owner for over 40 years and kept putting off buying a robot. Just didn’t think they were at the level of my “manual” vacuuming. We moved to a home in NC and the pool we inherited came with a Polaris robot. Amusing as it was, it basically stirred-up the water so the pool filter could clean the finer water dust and debris. The netted bag let much of the fine particles through and I had to keep the booster pump going while it ran, costing more money. My local pool company talked me into buying one of these Dolphins and it was the best thing I’ve ever done for me and my pool. It never “stirs-up” debris and cleans my large L-shaped pool in approximately 3 hours. Now I have more time to spend enjoying the pool with friends and family and enjoying a really clean pool!

Rating Stars
Does its Job

Ken -

Works excellent! Only complaint is it is a bit bulky. Cleans very well. Climbs partway up the walls.

Rating Stars
Doesn’t clean the stairs

Trish -

It does a good job but doesn’t clean the stairs or one corner of the pool where dust collects. I keep thinking we are missing something like a stair cleaning attachment.

Rating Stars
Great Pool Robot

Marc Downing -

My M400 does a great job of keeping my pool sparkling clean. Watching it work, it generally gets 90-95% of the pool cleaned. I do have a fiberglass freeform so the bot doesn’t get the top step or in one of the tighter curves but its consistent on the other cleaning. little elbow grease on those 2 spots and the robot does the rest.

Rating Stars
Almost Perfect

Larry Faust -

A great machine that does a fine job cleaning. I wish a little more effort was made to make the filter cartridges a little sturdier but other than that its an A+ all the way.

Rating Stars
4 Stars

Jerome Lawson -

Spend lots of time cleaning the filters

Rating Stars
Much better than my last Dolphin

Dave Chance -

I bought and used a Dolphin Diagnostic between 8 and 10 years ago. It did a nice job cleaning until the memory partially failed and it then would only go into about 3/4 of the pool. Also, the bag was a major pain to clean. The new M400 is greatly improved in both the coverage of the pool (20? x 40? gunite) and the 2 plastic/screen collectors are easy to remove and clean. The swivel device for the hose is an improvement, but still requires some kink straightening. Overall, a very good cleaner.

Rating Stars
Perfect......Almost

T Kinney -

Going into our third season with our M400. A great product and I would rate it absolutely perfect but for one thing. I find that it does not actually clean the waterline as a continuous operation. The machine climbs the side of the pool and cleans an area about its own width then goes back to the bottom and on to another area. I have never seen it completely clean the waterline for the full circumference of our 20 X 40 liner pool. No complaints about any other features. The M400, overall, does a great job and I absolutely recommend it.

Rating Stars
Buyers beware!!!

John A. -

Buyers beware!!!! Three years ago doing a lot of research I bought a M400 Dolphin. It has been in the shop every year since. The first year the brush on the bottom were loosing its knobs and had to be replaced under warranty. The second year the cord from the cart to the unit in the pool kept tangling up and pulling the cart from the wall. The swivel was not letting the cord swivel also replaced under warranty. Now this year. Took the Dolphin out of the pool house plugged it in nothing. Circuit breaker to unit was checked OK. Got my multimeter out 119.9 volts at receptacle. Took cord to supply unit checked voltage 119.9. Took to pool place where I bought it they checked it out motherboard was fried. $484.00 not in warranty out of warranty by one month. Worked fine last year when I put it up. Was in pool house all winter. I take care of my stuff but am sure disappointed with this unit.

Rating Stars
Could be better

Micah -

Unit consistently gets stuck trying to go up a corner stair and doesn’t do anything until I remove it. Not sure why but would be good if it actually tried to get itself off. Means I can’t just leave it for a few hours and then come back. Has happened every time I have used the machine (which is only twice, but still, 2 for 2). M400 does not climb any of our stairs at all and does not get up to the fairly deep tanning ledge (which I sort of expected but still a bit disappointing because the steps are pretty wide and it doesn’t even try). M400 does not climb over a small safety ledge around the pool so does not clean the waterline at all. Would have been pretty easy for it to just try to keep going but it doesn’t. Seems like it was not designed or programmed to try to climb over anything. Finally, I just found out that Maytronics seems to sell a brush specifically designed for fiberglass pools, which would have been nice to know on the website (and should have been an option as part of the base set). No clue where to find it or how much it costs because there are no details on Maytronics’ website. Just going on scraps from various forums. Will use it, but knowing what I know now I would have tried another product or brand. Some of these issues might not be any better, but there would at least be a chance.

Rating Stars
Buyers beware!!!

John A.  -

Buyers beware!!!! Three years ago doing a lot of research I bought a M400 Dolphin. It has been in the shop every year since. The first year the brush on the bottom were loosing its knobs and had to be replaced under warranty. The second year the cord from the cart to the unit in the pool kept tangling up and pulling the cart from the wall. The swivel was not letting the cord swivel also replaced under warranty. Now this year. Took the Dolphin out of the pool house plugged it in nothing. Circuit breaker to unit was checked OK. Got my multimeter out 119.9 volts at receptacle. Took cord to supply unit checked voltage 119.9. Took to pool place where I bought it they checked it out motherboard was fried. $484.00 not in warranty out of warranty by one month. Worked fine last year when I put it up. Was in pool house all winter. I take care of my stuff but am sure disappointed with this unit.

Rating Stars
Could be better

Micah -

Unit consistently gets stuck trying to go up a corner stair and doesn’t do anything until I remove it. Not sure why but would be good if it actually tried to get itself off. Means I can’t just leave it for a few hours and then come back. Has happened every time I have used the machine (which is only twice, but still, 2 for 2). M400 does not climb any of our stairs at all and does not get up to the fairly deep tanning ledge (which I sort of expected but still a bit disappointing because the steps are pretty wide and it doesn’t even try). M400 does not climb over a small safety ledge around the pool so does not clean the waterline at all. Would have been pretty easy for it to just try to keep going but it doesn’t. Seems like it was not designed or programmed to try to climb over anything. Finally, I just found out that Maytronics seems to sell a brush specifically designed for fiberglass pools, which would have been nice to know on the website (and should have been an option as part of the base set). No clue where to find it or how much it costs because there are no details on Maytronics’ website. Just going on scraps from various forums. Will use it, but knowing what I know now I would have tried another product or brand. Some of these issues might not be any better, but there would at least be a chance.

Rating Stars
Disappointing to say the least.

Edward -

Used it for a full season and it still had not mapped the entire pool. many spots are left that are simply not cleaned. Does not climb stairs well either. For the money I expected more. Would not buy this product again. The only positive I can find is that the unit is easy to clean, which does not make up for the extra time I need to spend cleaning the missed areas.

Rating Stars
High Price Manual Cleaner with Marginal Results

Jim Reece -

I purchased the M-400 robotic cleaner about a month ago. So this review is after 1 month of use. I paid over $1,300 for this unit, and so I expected a lot more than I got. First, the good thing is that it cleans the floor of my pool well. I like the dual rotor action, the two different filter options (mesh and pleated) and I like the cart with rollers. However, it does a poor job cleaning the walls and steps of my pool. And I have never seen it try to clean the skum line. I also have a tanning l

edge that is about 1? deep and the M-400 won’t even attempt to go there. I assumed that a $1,300+ cleaner today would be wi-fi compatible and have scheduling features. This cleaner has neither. I even called Maytronics to verify I was not missing something. It does have blue tooth, but that’s dumb because you have to be within a few feet of the unit for your phone to connect. And since it’s a basic on/off unit, the only thing you can do is turn it on. And since you have to be within a few feet for blue tooth to work, it’s much simpler to just press the button on the power unit. Not having any schedule features is a huge negative too. So when I am on vacation, there is no way for the M-400 to clean my pool unless I have someone drop by and manually start it. My pool pumps, sheer descent, deck jets and even my irrigation system is wi-fi compatible with scheduling features, so I can automate their function and operate them from my phone or a web site from anywhere in the world. Had I known the M-400 would not clean my walls very well and that it was a basic on/off cleaner, I would have saved $1,000 and bought a much cheaper cleaner. The M-400 is a huge rip off

Rating Stars
M400 stopped working 20 days out of warranty

Robert -

Unit was working great for the first 3years. stopped clean the walls took it to pool company where i got it. they said to adjust the handle side ways . worked for a week and then stopped running . took it back they said motor shot. now waiting to see if any thing an be done .