Algae problem - draining, steps / cautions to keep in mind?

Oct 19, 2015
11
Chandler, AZ
I got tired of my algae problem, so I'm draining my pool. Got a sump pump, and it's going on right now. I'm brushing from time to time as I can. I'm in Phoenix, day time highs 90-92 for the next 4 days. Any specific steps to keep in mind during / after this process.

I've a Pentair CCP-520, and I'm also replacing the cartridges since they needed to be cleaned up too quickly (based on pressure difference) even before the algae went crazy.

Steps I'm expecting to take:
  • complete drain, brushing as I can
  • refill
  • put a lot of chlorine.
  • get chemicals reading
  • replace cartridge
  • run the filter pump for a few days
Anything I should add to this todo list?
 
72, you didn't mention anything about the TFP SLAM Process. Have you read that yet? It's still a bit early in the southwest to be draining a pool with that heat and sun, so you'd need to fill it back ASAP. Also, I don't see it in your signature, so how are you testing your water? TF-100 or Taylor K-2006C? That is a must for the SLAM Process. It's very possible that a drain could be beneficial for you if your CH and CYA are elevated, but only accurate test readings would confirm.

So before you remove too much water, I would first ask you to answer those questions above (SLAM and test kit). Post a full set of water results as well so we can see what's happening. Also remember that the amount of chlorine added to remove algae is based on the current CYA and referencing the FC/CYA Levels. But follow the SLAM Process page and it will work. Let us know if you have more questions.
 
Thanks for the comments, folks.

My test kit is Taylor-k2006, which I've used for the last couple years. My last readings were pretty abysmal:
FC: 1, CC: 1, pH: 8.0, CYA: 40

I did read up on the SLAM method, but I just couldn't get the chlorine levels up. Thinking about how much Cl I'll have to buy (logistics and cost), that pushed me to the draining method.

Recently (last 6-8 months), I had switched to the Hasapool sodium hypo-chlorite (12.5%), bought at AM Corson's. Previously used the Costco bleach for a couple years. I have no proof, but am wondering if hasapool is not delivering the chlorine strength it's supposed to. Price-wise they are similar, so I'm going to switch back to Costco.
 
so I'm going to switch back to Costco.
Costco only sells Clorox bleach. Clorox contains Cloromax, which is not appropriate for pool use.

With your low CYA, I do not see why you drained, unless your CH was very high.
 
You should be checking new batches to see if what you added, brings your FC level to where it is supposed to be.

I have no way to check the batch dates for Hasapool. Just my own testing, which I didn't do a very thorough job of. Hence, just my gut feel.

Costco only sells Clorox bleach. Clorox contains Cloromax, which is not appropriate for pool use.

With your low CYA, I do not see why you drained, unless your CH was very high.

My last CH reading was pretty high, @ 475.

Looking at the HomeDepot option as well. Do you have experience / info about it?
 
CH of 475 is not high at all. You had a couple more years most likely with that water.

I have used the Home Depot 10% liquid chlorine. Biggest down side is they store it outside so the high temperatures degrade it. Check the Julian date on the box and only buy what was bottled the last 30-45 days.
 

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So I'm finished with my pool drain, cleanup, new filter cartridges, etc. See this thread for some discussion. The pool looks pretty now :)

My readings for today are:

DATE___ FC CC pH TA CH CYA Salt Borate Temp CSI
10/8/19 3.0 0.0 7.2 90 200 20 n/a n/a 85 -0.38


With CYA that low, I'm guessing the Chlorine will vanish fast. So I'm thinking the first thing I need to get in control is the CYA. Bring it up to 30-40, with stabilizer. I'll keep poring Home Depot hypochlorite to keep FC to >3.

 
Please enter your test data into your Poolmath app. You are sharing the data. It is very difficult to decipher the results as presented above.
 
Thank you!
I would add 20 ppm of CYA using the sock method. Maintain your FC based on 40 ppm CYA level. Test your CYA a week after it is fully dissolved.

Let you pH drift up to 8. Adjust no lower than 7.6.

Good job.
 
Also - if you have not since you exchanged some water, you might do a OCLT. Prior to adding any CYA.
 
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