Zodiac OT15

Reliable . .. but . . Doesn't do fine particles at all well – Good-ish, easy to use but does not pickup fine dust/algae. It blows it back out the top, so might as well use a manual vacuum every 2 weeks. Tried both the 200 micron and 100 micron bought with. Show details

OK for the money – picks up standard debris. Doesn't do steps, but most won't anyway. Doesn't clean fine particles Lightweight easy use. upgraded to a dolphin x30 very happy now Good for price point hough. thanks Show details

Does its job – Not a bad pool cleaner.Got sick of constantly replace parts on my creepy crawler the unit does a good job on pool walls and I havent had to hand vac the pool since buying the unit. I find it relaxing sitting by the pool Watching it do its thing. Show details

Great product! – Firstly, the review by RGB is top class and should be cross referenced in the TX30/35 reviews as comprehensive comparison of models. I've had my OT15 for over a year and can't speak highly enough of it. We have a smallish (7.5m x 3.5) kidney pebblecrete pool. We get a moderate amount of leaves but I just let them sit there and put the robot in… Read more

every two weeks which probably helps with the life of the unit. I'm amazed but it picks up mostly everything in one cycle, sometimes I put it on for two if there are a lot of leaves. It sometimes misses only longer palm leaves but if soft can get them too. Probably because I leave it for the longer, it can get the softer leaves and debris, but honestly I don't know why people spend so much time daily cleaning to get a spotless pool. We also live near a busy road and the beach and I find it picks up lots of finer sand and grit.

It also does a great job climbing up the side of ours - its about 1.8m at deep point. Sometimes goes sideways, backwards, flips and cartwheels but I think the randomness does a great job. Just set it and grab it out 2 hours later. It doesn't always get some of the steps, but whatever you can't expect everything. It gets them eventually.

Cord length is fine for us. We have a power point about 5 metres from the pool. I just chuck most of the cord in the centre of our pool and it doesn't get too tangled.

I always take it out of the pool after use and rinse it thoroughly with fresh water which might be why I haven't had any problems. Anyone leaving any equipment like this in harsh sunny environment or saltwater is asking for problems.

Best of the all the price is awesome! I haven't had to touch a pool scoop for months! This is my first robot but did read reviews of expensive robots with people complaining about the same things.

Good value available in OT15 – Here is the bottom line: with a few adjustments to your technique, this robot is reasonably effective as a pool cleaner (3*). It is seemingly without peer below $900 (5*). So overall it earns 4*. Now for the detail. First, note that the Zodiac TX30 (TX 35 without trolley) is with three exceptions identical to the Zodiac OT15 and FX18 cleaners. The… Read more

exceptions are: (i) price: the TX30 is intended to be sold through full-service pool shops, so it is much more expensive than the OT15 and FX18 which are intended for on-line stores and available on sale (if you are patient) with both 200 micron and 100 micron filters for less than $800 delivered. (ii) plastic colours: including the filter lid which is clear on the TX30 but opaque on the cheaper versions (it does not matter, as you should empty and clean the filter after every use). (iii) cord length: the TX30 with 16.5m cable is advertised to clean a 10m x 5m pool, whereas the cheaper versions with 14m cable are advertised to clean an 8m x 4m pool. In reality they will clean a somewhat larger pool, depending on placement of the control unit (see below).

Some retailers state that these units can be switched between floor only and floor plus wall modes. They can not. All are single-mode (floor plus wall) with a 2.5 hr cleaning cycle. If you want only floor cleaning, look at the cheaper TX20. If you want a trolley, you can buy it separately, or as part of the TX35. There are variants of each model for tiled pools. You can also buy spare brushes, tracks and filters (which are the same for all of these models). I have tested the OT15 in a salt-water chlorinated, pebblecrete pool that gets a moderate number of leaves and occasional heavy load of fine debris (probably Casuarina pollen).

There are some contradictions between instructions given by Zodiac in the owner’s manual vs the box. The manual says to insert the cleaner (anywhere?) and spread all of the (floating) cable in the pool; the box says to insert the cleaner near the centre of the long side of the pool, and only use the length of cable needed for your size pool. I obey the box for fewer tangles. The manual says to untangle the cord after every cleaning cycle, then to dry and store the cleaner out of direct sunlight; the box says to lay the cable out in the sun after use and then only loosely coil it to avoid permanent kinks. I do both. The manual says “Zodiac recommends only three cleaning cycles per week”; the box says “Do not exceed more than three cleaning cycles per week” (sic). You decide. It does not inspire great confidence that the manual says “please retain the original carton to transport your cleaner” for warranty service. Seriously? Where does Zodiac think we store the boxes for all our household appliances?

This is a very simple unit. There is only one button on the control unit, to start (or manually stop) the timed cleaning cycle. You can not programme it to come on while you are away on a holiday. There is no function to bring the unit to the edge or surface, so you must pull the cord, then use the handle before lifting it from the water (which you should do after each cycle). There is no way to send it where you want it. Unlike an old suction thumper where you could pull on the hose to place the cleaner in a dirty area, you should not pull on the power cable while a robot is running. There is no cable swivel. The manual says “The power cable may become tangled if correct procedure is not followed after each cleaning cycle”. My experience is that the cable tangles when new and also after loose coiling for a few days, but the problem decreases after a day or two in the sun, laid straight to help erase the memory of “storage loops”.

This cleaner needs a (weatherproof) power point with RCD (core imbalance or earth leakage protection), preferably located 3.5m-5.3m away, at a right angle (90º), from the centre of the long edge of the pool. This is because the power cord to the control unit is only 1.8m, and you should not use an extension cord (unattended outdoor shock hazard). Ideally the control unit should be 3.5m from the pool edge (or otherwise secured against movement, as it carries 240V AC and it is not submersible). This is to minimise risk of electrocution while maximising remaining (30V DC) cable length to the submersible cleaner head in larger pools. My pool is straight on one long side and lobed on the other, roughly 8m x 4.3m-5.5m, with rounded corners and floor-wall joins except at the steps which are nearly square joins. Fortunately, there is a power point about 3.5m diagonally away from one corner, so I use the OT15 with its cable run along the paving at the pool edge to the centre lobe, from which it easily reaches all parts of the pool. Check your required cable length before you buy. Use simple trigonometry, or run out a rope then measure it. Don’t forget to allow for pool depth at the corners most distant from the point of cable entry, and allow a little extra for the cable to flex without stalling the robot.

As others have noted, the Zodiac TX30/OT15/FX18 spends a lot of time in reverse and performing underwater acrobatics, during which it does not vacuum but rather spreads debris from the floor. This is probably part of the design to get the device to (randomly) cover all of the floor without getting stuck in any corner, or forever re-climbing the same wall section, or excessively tangling the cord over a 2.5hr cleaning cycle. Overall the approach seems moderately effective, if not very efficient. The device is advertised with “robotic intelligence” (whatever that means); but it certainly does not “map” the pool. It seems to move in a random pattern with all that reversing and underwater gyration throughout the cleaning cycle. One effect of this method is that the cleaner does not collect all of the fine debris from the pool floor on its first (or second, or third) cycle. In fact, it will make a pool very cloudy if there is a high initial load of settled fine debris to suspend. Under these circumstances, it may be a robot, but it is not much of a cleaner.

This clouding of the pool water by stirred-up sediment from the floor occurs even if the pool looks quite clean. All outdoor pools have some sediment from settling of debris that falls continuously on the water surface. Pool cleaning should remove this sediment, not re-suspend it. The best adjustment is to start the robot and the normal skimmer-filter (with a skimmer sock) at the same time, so that some of the debris thrown up by the robot is collected in the filter sock. Then clean both the robot cartridge and the filter sock at the end of the robot cycle, and keep the skimmer running to catch more of the suspended debris. With this adjustment, the clouding effect in an otherwise clean-looking pool diminishes after about a week (3-4 robot cycles), even using the 200 micron filter. It may simply be that the robot is more effective than the previous cleaner at suspending (and with the help of the main pool filter eventually capturing) fine debris on the pool floor.

The Zodiac TX30/OT15/FX18 brush rotates at the same speed as the front wheels. This looks and sounds impressive when the unit climbs a wall to the water surface and spins the wheels, but some more expensive robots have higher brush speeds for more scrubbing of the pool floor and wall surfaces, which helps to prevent biofilm formation.   

Wall-climbing (and any surface skimming at the top of wall climbs) depends on thrust from the water exiting the filter cartridge. With a clean 200 micron cartridge, this robot sometimes climbs to the top of 2m walls. It does not climb every time it hits a wall, and sometimes it runs horizontally along a wall. The thrust is less with the 100 micron cartridge, or with debris accumulated in the cartridge; so although the cleaner is rated to 4m depth, in this condition it is usually unable to climb more that about 1m up a wall. It does climb onto step areas, which is just as well as it blows debris up onto those areas. But it does not spend long on the step platform, because it usually backs off quickly after hitting a wall. Occasionally, the cleaner comes to grief when it gets stuck sucking air on the shallow top step of my pool. It is designed to switch off after a while if it can not “back out” of this situation. I guess I will have to keep brushing these areas manually.

The robot often just runs over leaves of the swamp oaks (Casuarina sp.) dragon plants (Dracaena sp.) and bottle brushes (Callistemon sp.) in my pool. Eventually it catches most leaves and Casuarina cones (except those on the step platform), but this may take several cleaning cycles using the 200 micron filter. The alternative is manually to scoop out most of the leaves. A much cheaper disk suction cleaner (thumper) does a quicker job than the robot on leaves, and on fine debris without clouding the pool. Relative to the robot, the suction cleaner has some disadvantages: (i) needs higher water level to avoid sucking air through the skimmer valve; (ii) slower set-up; (iii) noisier; (iv) needs much closer watching to move it out of the step corners; (v) less convenient filter cleaning; (vi) may use more power for faster pump speeds and more water for backflushing; (vii) no step or wall cleaning; (viii) lacks the brushing action that may help to prevent algal colonies from establishing. If these disadvantages do not concern you (and assuming that you manually brush the walls and steps to help prevent algal colonies), the disk suction device is a more effective pool floor cleaner than the robot, at about ¼ of the price.

If you buy this robot as an easy way to clean up a pool with a high existing load of fine debris you will be disappointed, even using the 100 micron filter cartridge. As a device to combine with some manual brushing and manual scooping of leaves from a pool that starts off looking clean, it is OK; provided you do not mind that it stirs up sediment from the floor to make outdoor pool water cloudy for the first week. On first use, my impression was that this is a 2* cleaner. After a few weeks of adapting my usage to suit its peculiarities, I am closer to rating its performance as 4*. With these cautions, and at $800, the OT15 is good value for a budget robotic pool cleaner, assuming it is trouble-free beyond its 2 yr warranty.

Edit: Well I am glad I kept the box for a while. After about 6 weeks the Zodiac OT15 died (wheels stopped turning). There was nothing visible caught in the mechanism. After a disappointing initial refusal, the retailer finally honoured their obligation to replace under statutory warranty. I hope it was a rare fault!