Intellichor Ic 40 Not Maintaining Chlorine

[tim01]

Hi Folks,

I have a perplexing problem with my new pool. The pool was completed a year ago with a pentair easytouch 2 body water computer and an IC 40 intellichlor chlorine generator installed. The pool capacity is 10,000 gallons and has a pebble tech finish and no spa. The IC 40 is oversized for the pool. I purchased the easytouch and intellichlor via the internet not being aware that it was possible to purchase a single body computer. I purposely over-sized the intellichlor unit.

When I first started the pool, under recommendation from the intellichlor manual, I did not connect the intellichlor to the easytouch computer, but did plumb it into the system. During the entire winter I did not connect the unit to the easytouch and used chlorine tabs. Last April I added the recommended amount of salt, connected the intellichlor unit to the easytouch computer and I have had trouble ever since.

The problem was the intellichlor unit did not seem to consistently produce chlorine and when it did it was either way to much or not enough. I tried many times adjusting the percentage on time and nothing seemed to work.

I contacted pentair tech support and they kept telling me my pool chemistry must be off even though I took samples into pinch a penny and they verified that all was well. This was on-going for about 4 months. Finally in frustration, I contacted a local service tech about a month ago, he came out and replace a computer board in the easythouch unit. I thought all was well until 2 weeks ago we had algae in the pool.

The percentage on time has been at 90% for the last 2 weeks. Yesterday morning I checked and had 0 chlorine in the pool. I left the percentage on time for the chlorinator to 90%. Now remember this is an IC 40 unit and a 10,000 gallon pool. The pump was on for 6 hours. I live in the Tampa bay area, FL. I checked the chlorine level right when the pool pump turned off and I got a reading of over 3ppm chlorine as would be expected. I got up this morning before the pump came on and the chlorine reading is 0.

Pool chemistry was checked yesterday and the only thing off was the alkalinity was a little low at 60. Stabilizer level is at 60.

Phosphates are 0.

What could have possibly eaten up all the chlorine over night?

I travel frequently so it's been difficult for me to determine if there is a trend to the chlorinator, but I've got my wife on board and she or I will check the chlorine level every morning and every evening to see if the chlorinator is consistently producing chlorine.

But I still can't figure out what happened to the chlorine last night. Any suggestions.

Tim

[chem geek]

Tim,

When there is algae in the pool, it can consume chlorine at fairly rapid rates. Even if the water is clear, there can be nascent algae that is not yet visible that can consume chlorine. The solution is to shock the pool with unstabilized chlorine, usually chlorinating liquid or bleach, and maintain the shock level until the overnight FC loss is <= 1 ppm. A reasonably fast shock level when the CYA is at 60 ppm is around 24 ppm FC. Read Defeating Algae for more details. Basically, when shocking a pool to kill algae, you maintain a high chlorine level not only until the algae is no longer visible, but until you do not have substantial overnight chlorine loss.

You could also check your filter and backwash it (or clean it as appropriate) since there may be dead algae still in it getting oxidized by chlorine.

After you have shocked the pool, note that you must target an FC in an SWG pool of at least around 5% of the CYA level, so for 60 ppm that's 3 ppm and for 80 ppm that's 4 ppm. So it's important that your CYA reading be accurate. I presume that you are using a Taylor K-2006 test kit since it has accurate and precise tests including a FAS-DPD chlorine test that can measure within 0.2 ppm for FC and CC (using a 25 ml sample; within 0.5 ppm using a 10 ml sample) and does not bleach out at high chlorine levels. You can get the kit at a good online price here or get the TF100 from tftestkits.net here with the latter kit having 36% more volume of reagents so is less expensive per test.

Richard

[Dicehyden]

Hi tim it could be more likely the algae particles as chem said. Just clean up walls specially corners with bleach and clean filters and nosel with bleach. I purchase chemicals for my pool from familyleisure Pool Supplies . You can try using batter chemical as well.