Help w/ above ground pool

[cholmes28]

I have been a TFP'er for 3 years, and have been able to solve most issues regarding my own pool just fine. My brother lives in Dallas, and just got an above ground vinyl pool. It is 5700 gallons, with a 2500gph pump. He has a Taylor K-2006, and has been testing. His water was perfect until a few days ago, and is now looking very green. When he brushes, he is definitely disturbing some type of residue on the bottom, and it looks green, not brown or yellow. I had him raise FC to to 15, then do an OCLT, and he is not losing any FC.

He is using 70% Cal-Hypo. His numbers now are FC 15, TA 160, pH 7.5, CYA 40.

At the pool store, they told him to put something called Green to Clean in, followed by some shock for 2 days, which he did, and the water cleared up significantly, but given what he was experiencing before, does anyone have any thoughts?

 

[jeffchap]

If he had algae, his FC got too low for his CYA at some point. It's as simple as that.

 

[cholmes28]

That makes sense, but if he had it, and the pool was green, wouldn't he fail the OCLT? He is literally not losing very my FC even during the day and zero at night. He kept FC at 15 for several days, and pool did not clear up. It has cleared up only since he put in the "green to clean".

 

[mknauss]

Green to Clean is Ammonium Sulfate. It works in killing algae, with ammonia. You then need large amounts of chlorine, far more than if a SLAM had been used, to eliminate the ammonia.

He needs to follow the protocol to eliminate the ammonia and then do a SLAM Process.

 

[cholmes28]

Thanks for that info. That explains why they told him to add a bunch of shock for next few days following green to clean application - he needs to get rid of the amonia. FC is holding at 15, which is about where he would be for a SLAM at a CYA of 40, so should he just maintain that level for a few days, then do another OCLT, and if no loss, he is in the clear?

 

[Texas Splash]

That makes sense, but if he had it, and the pool was green, wouldn't he fail the OCLT?

You would think so, but it doesn't always work that way. Might depend on the stage of algae, amount, and how aggressive it was growing. In any case, what you are describing sounds just like an algae bloom and algae settling at the bottom. Mine did that before TFP. Sounds like a SLAM Process is in order. Just make sure he passes all 3 criteria. The other products added might have just given him some false hope for now.

 

[mknauss]

If he passes the three criteria for a successful SLAM, then return to Target level FC based on CYA.