Rain and Green Water

[Vince-1961]

Re: Elks Pool - - - 55,000 gallons, uses pucks for chlorination. 1960's in ground concrete pool.

Okay, last weekend, my fellow "pool committee" members and I fell down on the job, meaning none of us went to the pool for 4 days straight and it turned dark green. All week I have been adding copious amounts of "liquid chlorine" (as the pool supplier insists on calling the 10.5% bleach - 2.5 gallons for about $7 - good price IMHO) for SLAMMING. Late yesterday afternoon, I go to add another jug (2.5 gallons) "LC" and decide that the water is almost clear so add only about a third of the jug, knowing that I had just put two fresh pucks of tri-chlor in the chlorinator. Testing showed FC around 5 or 6.

This morning the pool was about halfway green! Yes, it rained last night. (TA & CH in range, pH low due to excess chlorine. Didn't have the Taylor white top chemical to test CYA, but pool was filled about a month ago and been using tri-chlor pucks since then, so CYA ought not to be too high or too low.)

What gives?

 

[Jimrahbe]

Vince,

SLAMing is a process with specific requirements which must be passed before you quit.. It sounds to me like you were just dumping in a bunch of Liquid Chlorine and hoping...

If you want to do a real SLAM, you must follow this process until done... SLAM Process

Thanks,

Jim R.

 

[Texas Splash]

Sounds like you didn't perform the SLAM Process properly or complete it to the point where you passed all 3 criteria. There's no way for us to know if your FC was actually at the proper SLAM level per the FC/CYA Levels, but you noted an FC of "around 5 or 6" so it was not at SLAM level. The pH could be low due to consistent use of chlorine tablets that are very acidic. At the same time they increase your CYA making the SLAM Process more difficult.

At this point I would recommend posting a full set of test results along with perhaps a picture of your water. We can help coach you more from there if you like.