No FC but pool is crystal clear

[Watermom]

You are right that evening is the best time to add bleach but since you basically have none in there, if you can, it would be best to also go ahead and add some now. (Probably need more in the evening, too, to get back to shock level.)

And yes, I know it seems funny that there could be an issue when your water is clear but sometimes you can't see stuff that is going on in there. Clear can be deceiving.

[JimK]

You are right that evening is the best time to add bleach but since you basically have none in there, if you can, it would be best to also go ahead and add some now. (Probably need more in the evening, too, to get back to shock level.)

And yes, I know it seems funny that there could be an issue when your water is clear but sometimes you can't see stuff that is going on in there. Clear can be deceiving.

+1

This spring I was dealing with the byproducts off CYA biodegrading over the winter. Just like the OP, my water was clear; there was no visual indication anything was amiss. After about 25 gal. of bleach CL levels finally held. Now I'm enjoying! (Yes, that's me in my pic)

[PoolDoc]

Ironically, what can happen if you have ammonia from biodegraded CYA, is that you end up with monochloramine in your pool. This is the same algaecide that you're trying to produce when you use "Yellow Out", "Mustard Master" or similar products.

Monochloramine is a VERY good algaecide, better than plain chlorine. The problem is that it's a fairly good people-cide! It doesn't actually kill people, but it will run them out the pool with burning eyes and itching or red skin!

Fortunately, it breaks down pretty quickly as you add MORE chlorine, but during the brief periods when it's present, it can do a number on the algae.

[soupy01833]

Added another 3 gallons of bleach last night. This morning it is gone again.

FC=0
TAC=.5
Alk=90
ph=7.2
CYA=40

Question= bleach is getting expensive as it is up to 2.50 or so per gallon. is 63% calcium hypochloride as effective as 8.25% sodium hypochloride? Is 1 ilb bag equivalent to 1 gallon of 8.25% bleach?

Thanks

[PoolDoc]

Check the available chlorine % --if that's 60% or higher, it's mostly undiluted cal hypo.

With a TA=90, you can probably use cal hypo OK -- but what is your calcium level? (How are you testing?)

To answer your question, a pound of cal hypo with 65% available chlorine is roughly equivalent to a gallon of 8% bleach, in chlorine added to your pool.

[soupy01833]

My Calcium levels are low at 160 so I am not concerned there. Does cal hypo raise or lower TA?

oh and until my taylor 2006 arrives I am using the walmart HTH 6in1

[PoolDoc]

It raises both TA and CH. It is possible -- with a sand filter -- to use cal hypo so that, once the pH + CA + CH are at saturation, the rise stops.

You're not at that point yet. But if you add cal hypo via the skimmer AND let your pH float, it will stabilize near saturation. This is not a great idea if you have a heater, and MUST not be done if you have ANY sort of feeder or chemicals ANYWHERE between the skimmer and the filter: cal hypo tends to react VERY BADLY if it comes into direct contact with any number of other chemicals, including forms of chlorine.

[soupy01833]

I went to ocean state job lot. they have liquid mega shock 12.5% sod cl for 2.99 a gallon. Bought 2 cases. It is cheaper than bleach right now. I added 2 last night. Levels high. woke up and back to nothing again.

TAC=.5
FC=0

CYA=40
TA=100
PH=7.2
calcium=160

[JimK]

I went to ocean state job lot. they have liquid mega shock 12.5% sod cl for 2.99 a gallon. Bought 2 cases. It is cheaper than bleach right now. I added 2 last night. Levels high. woke up and back to nothing again.

TAC=.5
FC=0

CYA=40
TA=100
PH=7.2
calcium=160

Keep at it, you'll get there.

[PoolDoc]

Losing chlorine overnight actually means you are accomplishing something: breaking down whatever residue is present in your pool. (Daytime loss is often just to sunlight.)