Quote Originally Posted by BigDave View Post
OOPS! I missed that.
PLEASE don't do that. Trichlor will add 6ppm CYA for every 10ppm FC. Your CYA is already in the unknown / unmanageable area, we don't want to add more!

You didn't give us a Calcium Hardness number (important for a plaster pool), If it's low, you can chlorinate with Calcium Hypochlorite, if it's not, Bleach or Liquid Chlorine (same thing, different concentrations) is your only practical alternative (Litium Hypochlorite is an alternative but is very expensive).

How did you come by the numbers you gave us?

We really need to get a range for your CYA before we can figure out the FC level and dosage to super-shock your pool (and if that's really what you want to do).

Some wall marts carry the HTH 6-way test kit (Check Availability) It is compatible with the Taylor K-2006 (it's made by Taylor) and includes a CYA test. It also includes an OTO based chlorine test which can give us gross estimates of the very high chlorine levels you'll need to kill the mustard algae. Let us know if you can pick one up, if not, then do get a cheap OTO / Phenol Red kit - you'll need it. Also, Order the Taylor K-2006.
I had my water tested at Leslies. their analysis said 100 PPM CYA. I can get it down a bit over time by draining and filter backflushing. My calcium hardness is 200 PPM. I just did a complete water change this winter as my TDS had hit 700.

What i have is a pail of 99% pure triclor powder, it has no CYA added. I have a friend in the pool business, so I can get my chemicals direct from SCP at wholesale. So what I need to know is how to convert this powder to PPM in the pool water