Recurring Algae

[Tom.B]

Ok... I've had an 18x36 for almost 15 years and now have a recurring algae problem. I want to start getting a handle on my chemistry and am tired of spending $1000/season on chemicals. It looks like I may have finally found the answer here. I guess I have a lot of reading to figure out what to do and to learn a new way to think about pool care.

I want to change half of our water to (maybe) get a fresh start. Is this a good idea or unnecessary? If I do it, are there any gotcha's I need to worry about? Like the liner becoming catiwhompass (discombobulated) ;-)

Looking forward to FINALLY getting into a new world of pool care. I have spent the past 5 years fighting algae... constantly!

[PoolDoc]

If it's recurring green algae (free floating), you probably just need to (a) get a K2006 kit, and use it, (b) master the CYA/Cl relationship per the Best Guess page, and (c) be consistent with chlorination.

But, if it's persistent mustard algae -- which is quite chlorine and algaecide resistant -- you may want to participate in the phosphate trials we're doing. You *still* have to do (a), (b), (c) above, but I'm looking at evidence that, with very low phosphate levels, you may not need the extreme chlorine levels that are sometime required.

We've generally recommended AGAINST using phosphate removers, because they have been sold indiscriminantly, often along side phosphate increasing stain and scale chemicals. But a small percentage of pools suffer from persistent and recurrent mustard algae for reasons we have not been able to discover. With these pools, low phosphate levels may offer effective and fairly economical relief.

If you're interested, the thread is here: http://www.poolforum.com/pf2/showthread.php?21409

Welcome to the forum!

[Tom.B]

Yea... forgot to mention it is just green algae. After fighting what we THOUGHT was mustard (it turned out to just be pollen and after spending another $1000 at the pool store), we keep an eye on phosphates now.

So are you saying a water change is not needed?

[PoolDoc]

Changing water may not hurt . . . but it's not going to solve your problem either.

The FIRST step is to get a good test kit -- and there's really only the one -- and start testing. If budget's not a problem, I'd recommend going with the K2006C, which has 2oz test bottles, instead of 3/4 oz: people tend to test a lot, while they're learning. Send us test results as soon as you have them.

Regarding phosphates, you need to get the Taylor kit for that, too. It's rather a pain to work with, but of all the ones I tested, it was the only one that was semi-reliable. Dealers are interested in selling stuff, not in accurate testing. There *are* some pool dealers out there, doing accurate testing, but they are a minority. And the only way to ID those is to have tested accurately yourself.

There's another factor to consider: dealers are NOTORIOUS for selling phosphate removers at the SAME TIME that they sell you phosphate increasers (stain/scale agents). If you want to manage phosphates, you have to manage both the levels IN your pool, and the levels ENTERING your pool, via pool store chemicals AND fill water. I wouldn't recommend that, at least not yet.

Instead, focus on (a) accurate testing to determine what the status of your pool is, and (b) consistent appropriate chlorination to levels corresponding to your CYA level. With green algae, odds are that your problem will be solved as soon as you do this routinely. (And you'll spend far less than $1,000 on chemicals for the season!)

[Tom.B]

And do I just goto Amazon to get one?

[PoolDoc]

Use the testkit link in my blue signature bar, above. A link to the correct phosphate kit is found in the phosphate remover thread, linked above, but here it is again:

Taylor Technologies K-1106 Phosphate test kit
Hach Company 562227 Phosphate Test Kit (Aqua-Check)

Kem-Tek phosphate remover (most phosphate removed per $ spent)

I'll go ahead and post the K2006 links, too:

K2006A
K2006C