I Love This Forum

[jkusmier]

New vinyl-lined pool installed late last summer - I've had sparkling water and very stable water chemistry since opening - and especially since doing my own testing for past 5-6 weeks since I got a Taylor K-2006.

I appreciate all I've learned here even more after visiting a friend's pool this morning. He told me he gets algae blooms after heavy rains, which made no sense to me. I checked his equipment and he has two Pentair IntelliChlor IC40's (his pool is ~ 50,000G) and they're both running at 80% output. I asked him what his pump run time is and he believes the pump runs 24/7.

The IC40 produces up to 1.4lbs of chlorine/day. Assuming his pump runs 24/7, his his two IC40's should be producing around 2 1/4 lbs of chlorine/day. The only conclusion I can come up with is that he has little or no CYA in his pool, hence his chlorine is breaking down as quickly as his SWG's can produce it.

Any thoughts?

[chem geek]

It could be that his CYA is too low, but it could also be that he's fighting a nascent algae bloom so is barely keeping up with algae growth. This can happen if his FC level is too low for the CYA level. The manufacturer recommendations of 1-3 ppm FC with 60-80 ppm CYA are not sufficient since you really need to maintain a minimum FC level of around 5% of the CYA level for an SWG pool. Shocking the pool with chlorinating liquid or 6% unscented bleach will let one get ahead of the algae growth. One can also use Borates both as an extra pH buffer, also to prevent scaling in the cell, and as a mild algaecide. This may let one turn down the SWG on-time. If algae growth is the issue, then there are other methods of controlling it such as use of a weekly PolyQuat 60 algaecide or use of a phosphate remover, but usually chlorine alone can resolve the issue.

[Swim-Inn]

New vinyl-lined pool installed late last summer - I've had sparkling water and very stable water chemistry since opening - and especially since doing my own testing for past 5-6 weeks since I got a Taylor K-2006.

I appreciate all I've learned here even more after visiting a friend's pool this morning. He told me he gets algae blooms after heavy rains, which made no sense to me. I checked his equipment and he has two Pentair IntelliChlor IC40's (his pool is ~ 50,000G) and they're both running at 80% output. I asked him what his pump run time is and he believes the pump runs 24/7.

The IC40 produces up to 1.4lbs of chlorine/day. Assuming his pump runs 24/7, his his two IC40's should be producing around 2 1/4 lbs of chlorine/day. The only conclusion I can come up with is that he has little or no CYA in his pool, hence his chlorine is breaking down as quickly as his SWG's can produce it.

Any thoughts?

Heavy rains = change in water chemistry. Rain water fills the pool and basically dilutes any chemicals levels you currently have.

Get him to test his chlorine level after the heavy rains - he may find that it has dropped. It will take time for the chlorinator to make up the lost chlorine and during this time algae is flourishing, and as per chem geeks advice, the algae starts eating any new chlorine produced up, so the chlorinator cannot catch back up.

Rain water also washes phosphates from fertilisers into your pool - given the fast algal bloom it's highly likely he has phosphates - he should do a test, it makes ideal growing conditions for algae.

Low chlorine levels + phosphates + hot weather = algae in 2-3 days

The easiest solution is to give it a chlorine boost after the rains.

All the best

http://www.SwimIn.com.au

[poseidonpools]

You are exactly right. Any rains or precipitation will change the chemistry of your swimming pool, sometimes drastically. Another factor is the heat of the swimming pool or any coverage. Pool covers, when on the pool when it is not in use, will trap some chemicals and help keep the water properly balanced. Heat and sun is also another danger to swimming pool water chemistry. Heat will evaporate the water & the chemicals disrupting your balance. Other factors that can effect chemistry are pool use, activity, number of people in the pool, etc.

We recommend to all of our customers that they check the pol chemistry every day during the summer, sometimes twice a day depending on the use of the swimming pool. These tests can be done with a standard ph / chlorine dropper test. It is also advisable to get a pool water specialist to come and test your pool water at least every month for more exact tests and levels of other chemical presences such as chlorine. If you are trying to cut costs, many pool shops offer free pool water analysis. Alternatively, you can purchase a massive text kit which will test for everything you need.

[jkusmier]

I'm happy to report that my pool water is so well-balanced (thanks to what I've learned here from Richard and others) that my water has been sparkling since opening - despite some intense storms that forced me to siphon 1-2 inches of water and vacuum alot of shredded leaves, etc. from the bottom of the pool.

My friend has these problems despite spending $600-700/season, plus chems, for someone to maintain his pool. I've spent less than a third of that, and just a few minutes every other day, and haven't had a single problem.

[chem geek]

Congratulations! And your welcome.

[iveywk]

The one thing that people need to keep in mind with their pool and if they have algae / clarity issues and they are using chlorine and if they have issues they just aren't using enough. On a 25000 gallon pool on the right weeks in June or July (more likely June because in Iowa we get way more rain in that month) it is possible to consume 20 - 30 LBS of CL2 in a given week just to keep the CL2 at the right levels. I have seen my parents pool use that much CL2 and he has it tested everyday. Think of chemicals in your pool kinda like gas in your car. It doesn't matter what you have used. Think of your pool as a car with clarity as a destination, and chlorine as gas to run the car, if your pool is cloudy it is going to take what it takes to get the pool clear. It doesn't matter if it takes 100 gallons to get to where you want to go, you still want to get there. It takes what it takes.

[jkusmier]

Problem was actually very simple - took my test kit and some AquaChek White strips over to my boss's house - his salt level tested at less than 2500ppm; FC was at 1.0 (tested at three different places around the pool). Didn't check for CC, assume he's got some w/ FC so low. His two SWG's are running at 80% but salt is so low he can't produce any chlorine.

50,000G pool, I told him to add 240lbs of solar salt and 6 gallons 6% generic bleach. He should be able to dial his SWG's down to 30% if he adds some CYA, but I'll let his pool maintenance guy earn his pay.