100+ temps for weeks - How to keep algae under control?

finydb

0
Jun 5, 2013
41
It's suppossed to be up to 108 this weekend, and I've been battling the algae for weeks already. I tried leaving the pump on high, but it's so hot even my motor got overheated. Ran the vaccum for 4 hours last night to give the pump a break, and turned it on low today. Any tips for keeping the algae under control when water temps are so high? The water is into the 90's . . .and the sun on my AG sides are making them turn green FAST! I don't like getting in the water when the clorine levels are really high, but do I have any other options?
 
the temp has nothing to do with it, if the free chlorine levels are below the amount related to your cya then
you will have algae in cold (around 55 or up) or warm water.

First thing you need to do is get a recommended test kit.
Pool store results will not cut it. They are seldom if ever accurate.

A TF-100 or Taylor K2006

then do all the tests and report back the numbers here for advice to get your pool sparkling
and algae free like never before.

At the very least we need free chlorine, combined chlorine and your CYA test results.
 
Hmmm . . . I have the K2006, and keep the clorine levels and CYA levels where they should be, and I still have to add a LOT more clorine than I'd like because the sun and the heat. Oh well. Thanks for the advice.
 
It looked fine this morning, but I didn't test. I had to spend 20 minutes getting the pump to work (overheated last night, left it on backwash on accident, and got QUITE the surprise when I turned it back on this morning! LOL) Added a gallon of bleach last night. Like I said, my levels are good . . . but it's just costing me a LOT more bleach than when the temps aren't this high.
 
Hotter water temperature will have the chlorine demand increase from anything chlorine is reacting with, including oxidation of CYA and of pool covers and even chlorine outgassing. However, if you are able to maintain the FC/CYA level, then algae should not grow. It sounds like the increased chlorine demand is making it hard for you to always stay above the minimum FC/CYA level. You'll need to target a higher FC accounting for this loss and yes that means you'll be adding more chlorine during these hot days.

The problem is that once you have an algae outbreak, the algae clumps take higher FC/CYA levels to kill them -- that is the purpose of a SLAM. It's far easier to prevent algae growth than it is to kill existing algae clumps once blooming. You might also have a circulation problem if the algae is growing in a place of poor circulation. Pointing the returns to improve bottom circulation might help. Brushing could also help but that's more manual effort -- usually you want to do that weekly or so, but with bad circulation it could need to be more frequent than that (hence better to fix the circulation problem more directly).

If you wanted to use less chlorine and target lower FC/CYA levels, then that requires something else to prevent algae growth such as algaecides or phosphate removers, but those are extra cost and of course more complicated (another chemical to use and another measurement to control). We also don't have any charts to guide you with respect to FC/CYA levels in that case.
 
I can attest to the horrid temps we've been having. My pool is borderline warm. As such, I run a fairly high CYA (60-ish), and even though my target FC is 7, I like to keep it at 10. That's just me. :) But I will say what others might key-in later in your opening statement ... if you have been battling algae for weeks, more than likely a true SLAM was never performed or completed thoroughly at that time which is why the algae can return so easily. So that may be something to consider.

To be sure, do an overnight test Pool School - Perform the Overnight FC Loss Test (OCLT) to see if you are losing any FC in the dark. When performing the OLCT, remember that if must be done when the sun has dropped – no sunlight on the pool. About 8 hours total is recommended. Also, your FC level should be elevated more than normal. Starting FC could be close to your SLAM level, but no lower than 10. Anything less and you may not receive an accurate portrayal of FC loss (by percentage), even if it’s only 1 ppm.

If you fail the OLCT, you KNOW you still have algae and will need to SLAM via Pool School - SLAM - Shock Level And Maintain.

Hope this helps, and stay cool!
 
Thanks! I'd been adding about a gallon 3-4 times a week, guess I'll need to step it up to 7! I've been brushing a couple of times a week, and running my vaccum a time or 2. I only have one return. I wasn't able to get in the pool and "stir it up" this weekend like I normally do (was out of town), so guess it's time to get in tonight, move the stairs and get the water circulating.
 
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