Raising CA level with HTH

[trauh]

I have a 25,000 gallon gunite pool. Based on my first real test results (FC 3.6, CC 0.2, Ph 7.2, CYA 50-60, Calcium 140, TA 80) and advice from the Testing Results forum, I need to raise my Calcium up to the 250 ppm range. I was advised to use a cal-hypo product (without stabilizer) to do that.

Checking locally I found that available as HTH, and I am told that it does not have stabilizer in it. It seems to be sold in 1 pound bags with 57% chlorine, and using the bleach calc I found that to raise my chlorine level 1 ppm I need to use 0.2 liters of bleach.

How do I convert from liters to pounds? I already accounted for the higher concentration of chlorine, so I am now officially confused. Thanks.

[sunofthebeach]

I don't know the answer to your question, but if it were me I would just add straight calcium to the pool and continue using what ever chlorine method you are using now.

[duraleigh]

trauh,

If you choose to use cal-hypo (calcium hypochlorite(, that's pretty much a pool store product. However, don't buy it in the 1lb bags........at least a 25 lb tub to get you thru the Summer....much cheaper.

You'll dose probably around 8-12 ounces by weight to raise your Cl by 2ppm.

The cost will work out fairly close to bleach and you will gain the advantage of not having to purchase any additional calcium

[trauh]

Yes, your estimate was exactly correct. I added a 1 lb. bag and FC rose from 3.4 to 6.2. I guess next time I'll know that 6 oz. will give roughly 1 ppm. I tried remeasuring Calcium level but there was no change. Maybe that takes more time to see a measurable increase...

Thanks to everyone for their help.