Algae On Walls

[built2prfctn]

Hi all, I'm sure this has been brought up before.
My pool chem is nearly perfect and looks great. But I constantly have to scrub the walls on my 18x36 in-ground at least 2-3 times a week to remove green algae.

My chlorine levels are sometimes a bit low. I usually keep (4) 3"tabs in all the time.
Does anyone use anything else to keep this from growing so quick? I was using Phosfree last year, but I dont think it really helps.

Any other suggestions?
Thanks!

 

[IceShadow]

Welcome!

We do things differently here from a lot of other pool care places and what you'll hear in stores, etc. We use science-based recommendations and understand better a relationship between FC/CYA that most common pool care completely ignores.

What's probably happening is that your tabs are adding FC and CYA both to the pool. The FC is used up by the algae or the sun, and is gone, while the CYA stays in the pool. Over time, the CYA builds up and the FC stays the same as you add more tabs - but if the FC gets too low compared to the CYA, the CYA won't let it kill things like it should.

What we would recommend you do is to get a handle on the chem levels in your pool using a titration/dropper style test kit. Get either a TFT-100 or a Taylor K-2006C (the C is important or you don't get enough of some of the chemicals you'll need for testing), and then you can post up results of your chem levels that we can help you with. Pool store testing has proven too unreliable for us to give advice on it, and test strips are called "guess strips" around here because of how inaccurate and imprecise they are.

If you do want to follow our methods, once you've ordered the kit, add 5ppm of liquid chlorine to the pool daily. I'd recommend stopping the use of the pucks until you can find out what CYA level the pool is at. They could be adding more.

Also - if you can fill out your signature with your pool, equipment, etc. info it will help us out. See mine as an example. (If you're using a mobile device you have to turn it sideways to see signatures.)

Again - welcome, and we hope you'll let us help you out!

 

[IceShadow]

Also, here's some videos on how we recommend pool management and some articles to read to see why we do things the way we do:





ABCs of Pool Water Chemistry

Test Kits Compared

 

[JoeSelf]

Your Free Chlorine (FC) levels are not high enough for your CYA (stabilizer). For every 10 ppm of FC you add from pucks, 8 ppm of CYA builds up. FC is used up but the CYA sticks around.

If you are going by the 1-3 FC recomendation from pool store, (too low) that's why you see the algae. FC/CYA Levels

We can help but need tests, by you, from your own test kit. Test Kits Compared