The Original Sinking and Floating Chlorine Dispenser for Pool, Uses Less Chlorine than a Floater, It Sinks - Cleans Water - Floats Back Up, Replaces Pool Chlorine Floater, Light Blue

Follow the directions and contraindications and it works perfectly. Uses much less chlorine than top floaters and keeps it where it needs to be and out of your lungs. My pool guy was skeptical but the ease of use and perfect water tests impressed him. I could never go back to the floating dispensers now.The pool overall is much nicer to use with the chlorine not concentrated in the top level, too.My in-ground pool has pale plaster and neither staining or discoloration has ever been a problem from the Sunken Treasure and this product doesn’t bother the pool cleaning robot.

I wanted very much to give this product a five star review. The concept is great and the product shipped quickly. My pool has sweeping jets on the bottom so I knew that I'd have no problem getting the chlorine to circulate, but therein lies my problem. While the dispenser gets pushed around by the jets, it sometimes comes apart leaving a naked chlorine tab (or two) on the floor of my pool. This direct contact stains the plaster. While it's functioning correctly though this does a great job of keeping enough chlorine in the pool to maintain sparkling clear water. And the unit, or its halves, dutifully float up when empty.I'm working out a way to better secure the halves using a nylon screw so this doesn't happen anymore, but I can't put a five star review on a product that requires modification of any sort to work correctly.UPDATE Fall 2014: The vendor reached out to me proactively to exchange my unit for another. Apparently, mine pops open more easily than it should. I've not tested the new unit yet, and won't until the spring, but I was very impressed by the vendor and I have every confidence that if I continue to have problems I'll get them resolved. Like I mentioned before, the unit works great other than the one, hopefully now resolved, issue.UPDATE Spring 2015: The replacement unit has proven itself solid and I've now purchased a second unit to help keep me going through the summer. With two tabs in each, they're keeping my chlorine at proper levels for about a month before they float up looking for more. My water temp is about 70 degrees at this point with my filter running 7 hours a day. I expect they'll run out faster as my water temperature rises in the summer, but I can confirm that these sink floats are working well and saving me money.

The Sinking Chlorine dispenser seems to work as advertised. It uses much less chlorine than the floating dispensers. I have both deployed. However, the Sinking Chlorine dispenser isn't tolerant of the cleaning BOT. The BOT will cause it to open and dump its tablets when it pushes it around. It is now necessary to remove the dispenser from the pool before using the BOT. This is done every day. At least until I can figure out how to make a better latch for the two halves. Because of this BOT intolerance, I only gave it four stars.An update is that I drilled a small hole on the rim where the two halves meet and used a small zip tie as a "lock" to prevent the two sides from sliding open. It's a simple fix to the problem, but I will need to cut the zip tie and put a new one on every time I add chlorine. At least I won't need to pull it out of the pool.

After reading all the positive reviews we were very excited to get the Sunken Treasure. We really liked the idea of not having a floating chlorine dispenser that always seemed to follow us around the pool, like our old one did. And, the idea of using less chlorine sounded great too.BUT unfortunately, this product doesn't seem to be working. We've had it a few weeks now and so far it has not performed the way it was advertised. We have a large 16x36 inground gunite pool with a 8-9' deep end. We dropped it into the deep end after filling it with two 3" chorine tablets, as instructed.(It specifically says to only put in 2 tablets regardless of the size of your pool.) It sunk to the bottom as it said it would, but after almost a week it had not floated back up to the top and when my husband checked the chlorine level of the pool water, it was almost non existent.He pulled out the Sunken Treasure and it still had about a 1/2 tablet in it...just enough to not let it rise but certainly not enough to chlorinate our pool. So, he filled it again, this time with 3 tablets and after 4 days we found it floating. We thought "oh good, it's working". But when we opened it there was still at least 2 tablets left in it.We couldn't figure out why it floated to the top this time when it didn't float to the top before when it had far less chlorine tabs in it. He added another tab to it and dropped it back into the pool again. It's still at the bottom and we're waiting to see what happens next.We've had to add additional chlorine tablets to the skimmer and also added liquid chlorine because so far this vessel doesn't seem to hold enough tablets to keep our pool at the required level. We use to have the other kind of chlorine tablet dispenser...the kind that floated on top and held about 4-5 tablets. That one seemed to work much better. We rarely had to add additional tablets to the skimmer...only when it was very hot and the chlorine dissipated more rapidly.We're really disappointed the Sunken Treasure isn't working better because we like the idea of not having the chlorine floating around where we swim but so far it's not adequately chlorinating out pool.Maybe it's OK for a smaller pool, really don't know. We'll give it a couple more trys but at over $30 it's too expensive to keep if it doesn't work as advertised.Update: 7/29/13 We never did send the Sunken Treasure back. Just wound up keeping it as an additional chlorinator. We still like the idea of it being at the bottom of the pool. We just adjust our chlorine level by adding additional tablets to the skimmer. The ST still does not work properly. It constantly floats to the top when it shouldn't. Most of the time there are 1 or 2 full size tablets still in it and it's floating. It has also discolored our light blue plaster. We found it had moved off the drain and was sitting on the bottom of the pool. When we moved it there was a yellowish stain that we can't remove. I would not recommend anyone buying this product unless these issues are resovled and the product is improved.