I need to add 30 pounds of calcium to our older fiberglass pool. How many pounds can I add at one time to if I'm only going to run the pump 8-10 hours after adding it? (I don't like to run the pump overnight because we've been experiencing problems with our pump lately.) When I've added a large amount of calcium like this in the past, I only added 5 pounds a day but it will take 6 days to get it all in there if I do this again. I added 20 pounds on the same day once and experienced staining afterwards so I'm always leery about adding too much calcium at one time.
Adding a large amount of calcium to pool
- Thread starter gwtw
- Start date
- Jul 21, 2013
- 53,286
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
No one really knows. Take it slow. If 5 lbs/day has worked for you then do that.
There is no rush to raise CH.
There is no rush to raise CH.
Calcium level is currently 160 and I'm trying to raise it to 350. Manufacturer recommends a calcium level of at least 300. The walls and floor chalk terribly when it is low on calcium and it usually goes away once I raise the calcium level to 350. Apparently, this is something that happens to some older fiberglass pools when they are low on calcium. Our pool is chalking so bad right now that it turns my hands white when I rub the walls and clouds the water temporarily when I brush the pool.
Got it.
As @ajw22 said - just take it slow. With the pump running I have just broadcast it over the pool walking completely around it. But, I've never added pounds to be honest.
FWIW, I have added 10 lb per day with no ill effects (or really any visible effect after about a minute). I nearly fill a 5 gal bucket with pool water and add no more than 5 lb at a time to the bucket. Add one lb at a time and stir. Feel the side of the bucket for warmth. If it’s getting warm, that’s enough for that bucket (like I said, I do 5 lb. per bucket, no issues, but safety first!). Two buckets does the 10 lb for the day. Retest the next AM, and do it again until you hit your target.
Note that a high pH will precipitate calcium so keep an eye on all the pool chemistry, not just CH, as you do the process (I know you do but just throwing this out there).
Note that a high pH will precipitate calcium so keep an eye on all the pool chemistry, not just CH, as you do the process (I know you do but just throwing this out there).