Fighting mustard algae....a losing battle? Bad pool design

[Flyguppy]

Please look at the pics attached. I have stone and masonry that abut the plaster in my pool....and is below the water line.

Many spots have cracked or have holes where algae can hide.....no way to brush out.

I've slammed my pool 3 or 4 times over the last 2 years. Each time, the OCLT has told me that I've been successful in killing the algae. That lasts for a few weeks, then it's back.

Particularly aggressive this time.....can't go 2 days without yellow walls.

Am I screwed until I get my pool redone and the mortar spots filled in? Any other suggestions?

 

[Texas Splash]

Well Brad, those nooks and crannies can definitely make things more difficult for you until you can get them sealed properly. But regardless, the treatment is virtually the same for most algae types we typically see (green, black, yellow/mustard, etc) - bleach, bleach, bleach. The only difference may be a Mustard Algae FC boost for 24 hrs as noted on the MA page. You're welcome to post a full set of current test results though if you would like the crowd to chime-in on suggestions.

 

[chem geek]

You can use last resort methods that, unlike chlorine alone, don't get depleted and are not dependent on good circulation.

 

[Donldson]

I am with chem geek, yours is one of those few cases where it might make sense to include polyquat or phosphate reducer in your management program. Raising your FC target would probably help but if algae is able to grow in the cracks then you will always have high chlorine demand and be at risk for another outbreak.

Of course, like you said, the best thing you can do is get the stonework redone as soon as you can. That should solve the problem once and for all.

 

[Flyguppy]

Sorry it took a bit....been out on a trip.

Latest results:

ph = 7.3
FC = 10.0 (still coming down after latest mustard shock)
CC = 0
TA = 110
CH = 275
CYA = 60

Know the CYA is a bit high.....but I'm forced to use chlorine tablets because I'm gone an average of 3 days per week. Wife isn't gonna be out there testing and bleaching.........

What's the best way to test for phosphates? Local pool store mentioned it when I was in the other day......to help with the algae issue. Will hopefully do a full drain and a replaster this fall....to include mortar work.

 

[Alex_H]

Good luck. Walmart Sold a Yellow Be Gone solution that really killed everything fast at a fraction of the cost of the stuff at the pool stores. Whether it causes other side effects or not I can't say, but it's a "no brush" system that does kill the algae. I'm not going to recommend it and get yelled at here, but I will say given the choice between the cheap stuff from Walmart or the expensive stuff at the pool store, the one at Walmart worked much better and was cheaper.

Phosphates feed the algae. Obviously, if you can be algae free, they are irrelevant (the general opinion here). OTOH, if you occasionally get algae, less phosphates means no blooms.

Obviously the real solution is what you are planning to do in the fall, the drain/replaster. It's unpopular here, but with only a few weeks/months to go, might be worth a short term fix so you can use your pool, since the long term chemical issues won't mater since you're draining in two months.

 

[Donldson]

It's unpopular here...

What is unpopular here is any suggestion that involves blindly dumping chemicals in or using products without knowing what is in them or what they will do. You are bringing up Yellow Gone, but do you know what is in it? If not then why are you even mentioning it? Here is a discussion explaining that it may help but will create a large chlorine demand, something OP probably doesn't want if he will not be available to monitor it: Diammonium Sulfate, YELLOW OUT I really do appreciate your desire to contribute, but you have some learning to do yourself on the TFPC system first.

@Brad: If you are going to be draining and replastering in a couple of months then I wouldn't mess with phosphate control or anything since the problem will be resolved soon. You can just maintain somewhat higher FC for the next couple of months I would think. Once you are done with that you may want to look in to the possibility of a stenner pump to deliver chlorine so you can continue using liquid chlorine even while gone. Being in Texas with stonework an SWG may not be a great idea, but a stenner will keep things going well while you are away without adding any additional CYA to your pool.