How many days at shock levels?

[rfera]

I opened my pool two days ago, backwashed and rinsed my filter and gave it an initial shock with a 1lb bag of ProTeam Power Magic AC Superoxidizer (Calc hypoch 47.6%; sodium tet 20.0%) and 12 oz of concentrated algaecide. I didn't test first as I hadn't found my strips yet. There was some brownish powdery substance on the bottom today when I brushed (all very loose and none on the sides) so I think it was probably a mix of some dead algae and pollen (apple trees downwind have been in full bloom this week and there were lots of petals and stamens in the skimmer).

Today my levels were:
TH: 250
TC: 3
FC: 3
pH: 8.4
TA: 120
CYA: 40

I added bleach to bring the FC up to 10 and then added muriatic acid to lower the pH to 7.2 and am aerating to try to bring the TA down a bit. The pool actually looks great!

How many days do I need to keep my pool at shock levels? I want to avoid the algae problems I had last year, so I'm willing to keep it up there as long as necessary, but don't really want to dump more chemicals in there than I have to.

 

[Isaac-1]

1, you need to get a good drop based test kit, see my signature, test strips just don't have enough resolution to tell you much of anything, simply too much margin of error.

Once you have a good test kit you can measure your overnight FC loss and CC level to know if you have an algae problem, then can treat it per pool school link in the upper right if you do. Right now it is anyones guess what is going on.

Ike

 

[BoDarville]

rfera:

Welcome to TFP

1, you need to get a good drop based test kit, see my signature, test strips just don't have enough resolution to tell you much of anything, simply too much margin of error.

^ What he said on the importance of getting a good test kit. This is the first thing I would do. Even more critical if you need to go through the Shock Process.

...12 oz of concentrated algaecide.

Algaecide is not needed to shock the pool nor is it needed for day-to-day maintenance. Proper chlorination for your CYA level will prevent algae.

I added bleach to bring the FC up to 10 and then added muriatic acid to lower the pH to 7.2

It is better to test and adjust pH when FC is within the target maintenance range for your CYA. Higher FC levels can throw off the results of the pH test which could lead you to overcompensate on it's adjustment.

How many days do I need to keep my pool at shock levels? I want to avoid the algae problems I had last year, so I'm willing to keep it up there as long as necessary, but don't really want to dump more chemicals in there than I have to.

Even with a proper test kit, the Shock Process cannot be time-boxed. What the proper test kit will do is prevent you from overdosing and wasting chemicals.