*SIGH* Looks Like I Have da' Mustard

[PoolDoc]

At least 24 hours -- and after vacuuming and backwashing. The material comes out, mostly on the filter.

[Tom.B]

At least 24 hours -- and after vacuuming and backwashing. The material comes out, mostly on the filter.

I'm not sure I completely understand this sentence. Can you clarify?

**EDIT**
Okay, so... PO4, in 12 hours after Kem-Tek, has doubled to 1000-ish. YIKES! (will retest)

FC-21.5
CC-.5
pH-7.4
TA-80
CH-340
CYA-60-70
PO4->1000

Pool still crystal clear with no overnight algae growth.

[PoolDoc]

The PO4 removers work by precipitating lanthanum phosphate particles. But the phosphate is not actually REMOVED from your pool, till those particles are filtered out, and backwashed (or washed, with cartridge filters) away.

I don't know enough about the phosphate test, to know whether it would register phosphate still present in the pool as unfiltered lanthanum phosphate particles.

I would treat PO4 removal as a week-long process: add the PO4 remover, filter and clean normally, and then -- after a week -- check your PO4 level. You might also want to retest the fill water when you do - PO4 levels in drinking water can vary, depending on what's happening at the treatment plant!

[Tom.B]

Will these particulates settle to the bottom of the pool or remain transient and just get caught in the filter?

[PoolDoc]

Honestly, I don't know. I *think* it mostly filters.

What puzzled me about using the Kem-Tek product was that I never saw any cloudiness, or particles -- but the PO4 level did come down. However, I was separating dosing and testing by a week or more.

[Tom.B]

I used 32oz. yesterday. I will wait and possibly do it again mid-week.

[Tom.B]

FYI--- Water is AMAZINGLY clear! I brushed the pool today and there were zero signs of algae. So far... so good.