Algaecide Question

[jennanne72]

This is our 4th pool season, and it certainly has been a challenge! We have had an unusually wet spring, followed by an extremely hot summer (pool temps in July reached 90, which is unheard of in western NY)! The algae and pollen has been a constant battle this year (we used the DE trick in the sand filter at the beginning of the season to clear the pollen and it worked beautifully)!

My question is about alagaecide... What is the best type to use and when should you use it? My father swears by the copper based algaecide and has a crystal clear pool (but does have stains on the bottom of the pool from it). In past years, we have used the Sam's Club or Walmart special without a problem (with 2 trichlor chlorine floaters). This year it does not really seem to be doing the trick and just leaves a slimy film on the surface. The floaters have also not been able to keep up and we have gone through much more chlorine than normal. Any advice would be helpful, thanks in advance!

Western NY
30,000 gallon IG Vinyl Majestic Pool
1.5 HP Hayward/Sand Filter

 

[Beamup]

Welcome!

Let me start by saying that algaecide is NOT the solution to an algae problem. Chlorine is. A properly chlorinated pool never needs algaecide, phosphate remover, or any of that other stuff the pool store tries to sell you.

Most likely, what's going on is that the use of trichlor has raised your CYA to the point that you would have to maintain an EXTREME chlorine concentration to be effective. What you should do about it:

1. Read Pool School. Particularly relevant will be Getting Started, Pool Chemistry (skip the article on SWGs since you don't have one), Defeating Algae, and Shock Your Pool. But eventually you'll want to read everything.
2. Get a good test kit (the TF100 is highly recommended, the K2006 is also good - there's an article in Pool School).
3. Read Pool School.
4. Post a full set of test results here. Pool store testing will do while the real kit is on the way. We need to know FC, CC, pH, TA, CH, and CYA.
5. Read Pool School.
6. Do what the experts here suggest based on the test results. This will involve going through the shock process detailed in Pool School, and may involve a partial drain/refill first to get the CYA level down. But it all depends on those test results, so that's the starting point.

As for algaecide, polyquat is what's recommended around here when an algaecide is called for. But that's mostly at closing (to inhibit algae growth over the off-season), and many people don't even need that. Copper-based are definitely not recommended, due to the staining they cause.

 

[jennanne72]

Thanks so much for your help! I just have cheap test strips that give "ranges" for pH, TA, FC and stabilizer (not CYA). My ranges all looked good, except for the stabilizer which is reading very low. I've not used the TF100 test strips and definitely will be getting some before adding more chemicals for pool closing (which is unfortunately in a few weeks). We usually drain the pool significantly at the end of the season, so this may be a great place to start!

 

[Beamup]

Stabilizer is another name for CYA. But test strips for that are particularly useless. I'd suggest getting a set of test results at the pool store - they won't be great, but better than strips. We'll also want the actual numbers, not just "looked good."

A description of how the water looks at the moment would be helpful also.

 

[jennanne72]

The pool is clear, it just looks dull this year as compared to years past and we have been fighting algae all summer. The pool store by me only does the test strips which I already have, and I am fully aware is totally useless, grrrr! I only posted "looks good" because it is the best I have at the moment. I have been reading "pool school" and will definitley be ordering a quality kit as suggested above, and prepping the pool for closing in a few weeks. I will definitely post numbers when I get the kit, thanks again!

 

[linen]

Sounds like you primary chlorine source is pucks in floater? Just use liquid chlorine/bleach for now until you can get good test numbers. You probably have high CYA (caused by those pucks) and need to do a partial drain. Let us know when you have those test results. For now study pool school, read all of it including: http://www.troublefreepool.com/pool-school/types_chlorine_pool

 

[frogabog]

When you get your kit, chances are the results will say you'll need to shock the pool. So brush up on the shocking information in pool school in the meantime. You may be in the position to just need to "finish shocking" which is pretty much the same as shocking but there's a chance it won't take too long if you've done enough damage to the algae already.

Wait on the algaecide, if not foregoing it entirely. Copper algaecide is never recommended here. Bleach/chlorine kills the algae, and the filters pick it up eventually when it's completely dead. Patience is required, we call it POP (Pool Owner Patience). It's free even :~}

Maybe try a different pool store that will use drop based reagents to test your water?