Help: algae bloom I can't control

[martink]

Water is looking good. On your picture the pH looks fine, but the TC looks pretty light. What is your FC level and are you keeping it in line with the recommended levels for your CYA?

I also checked your PoolMath logs and seems like you are adding 64oz of liquid chlorine on a daily basis. That only adds 2.8 FC to your pool. I bet your normal FC loss on a daily basis is 3-5, which means you are not replenishing the chlorine you are losing on a daily basis.

Here is a chart I use to help me stay in range. Your most recent CYA was 30, but you have also used some trichlor which will add some CYA. I would test your CYA, then get chlorine into the correct range. I treat the lower number of the target range as my minimum and get panicky if by FC gets near there. For example, if your CYA is now 40, I would dose my chlorine to bring my FC up to 8 or 9 so that when the FC gets used up you spend most of the day in the target FC range and stay well above the minimum.

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I am keeping the chlorinator full of tabs all the time, the 64oz is supplemental for the peace of mind. I test FC and CYA weekly and TC daily. The FC is usually from 4-5. I adjust PH weekly.

Once the CYA reaches 50-60. I will stop tabs and use liquid chlorine only till CYA gets below 30 (rain water dilution)

 

[Mdragger88]

Here’s what each dissolved tab does to your water

That means 5 dissolved tabs = 9ppm cya -
this can happen fairly quickly & put you behind the 8 ball in terms of proper chlorination. Stay vigilant.

 

[JJ_Tex]

I am keeping the chlorinator full of tabs all the time, the 64oz is supplemental for the peace of mind. I test FC and CYA weekly and TC daily. The FC is usually from 4-5. I adjust PH weekly.

Once the CYA reaches 50-60. I will stop tabs and use liquid chlorine only till CYA gets below 30 (rain water dilution)

Ok, but for the record your low FC is giving me an ulcer. FC of 4-5 is below the target range for CYA of 40. Once you get to CYA of 50-60 that will be too low of FC and you will likely get algae at those levels. Make sure you are following the FC/CYA chart and keeping your FC at the appropriate level.

Remember, it is totally safe to dose above your target FC so that you pool spends the majority of the day in the target range.

 

[Mdragger88]

Ok, but for the record your low FC is giving me an ulcer.

Same!

 

[JeanZ1]

Same!

As well as the weekly testing of FC

 

[Bperry]

I passed the CC of 0.5 or lower. But haven't had the change to do the overnight test as I was not home for 2 days. No visible algae dead or alive.

I want to enjoy the pool and not keep slamming it all summer. Will deal with issues when they arrise and do another full SLAM in the winter when the pool is not used as much

Just wanted to note that it’s perfectly safe to swim during the SLAM. No reason to not enjoy the pool.