New plaster -- need chemicals balanced

Rental Pool

Well-known member
Aug 7, 2015
128
Saugus, CA
I had the pool replastered 5 days ago. At the time, I tested the tap water and found it to be TA of 290 and CH of 330. After I filled the pool, 8 hours after the plastering was done, here is what the pool water tests at:

FC = 0.2
CC = 1.4
pH = 8+
drops to 7.4 = 4
TA = 150
CH = 150
CYA = 0

There has been no plaster dust in the pool, and the pool is crystal clear. I have been brushing/vacuuming. I have only added 2 quarts of The Blue Stuff and nothing else. What do you recommend I add at this time? Should I start my Stenner chlorine pump? Should I put in any chemicals before I do that? Thank you.
 
Probably the first thing we need to advise you to do is check with your contractor to ensure you are following what they want you to do first to ensure you retain any warranty period on that new plaster. Once they give you the green light to proceed on your own, start here: Pool School - Start-up New Plaster. Read that page carefully.

You'll find that acid consumption will go up as the plaster cures to keep the pH in the mid 7s. In addition, you need stabilizer in the water for your CYA right away. Add enough stabilizer for an initial goal of 30 ppm using the Poolmath calculator . Yes, you also want more FC, but until you get some stabilizer in the water, keep it at about 2-3ppm. After you add stabilizer, increase FC to about 5ppm.

Your CC (trash chlorine) is quite elevated. You may have a potential algae bloom trying to start, so get that FC higher right away. You can use regular liquid bleach for now if needed until you get the Stenner going. This should help get you going for now. Watch that water clarity and CC reading in case we need to get more aggressive against algae in the near future. Hopefully not, but you never know.
 
+1 on doing what the company providing your warranty says to do first of all. Keep PH at 7.8 or less at all times, this is very important. Enter all your test results in Poolmath and monitor your CSI. Keep it in range at all times, or even a little tighter range of +/- 0.5. That is a really high TA, which will cause your PH to rise so test PH often and work to lower your TA, Pool School - Lower Total Alkalinity. And keep your CH above 250 ppm.
 
I am following the contractor's directions. According to the Poolmath calculator, I need 123oz of 10% chlorine to get to 5.0 and 107 oz of stabilizer to get to 40. I'll put in 6# (96oz) of stabilizer and then see if I need to increase it. I'll turn on my Stenner and start pumping chlorine into the pool to gradually build the chlorine as the stabilizer dissolves. I'll be using Clorox Stabilizer from Lowes, unless you feel the Leslie brand would be better. Should I do anything with my TA or CH? The calculator shows a CSI of .74. Is that a problem? Should I lower the pH to 7.9?
 
I put in just under what was stated on the calculator, as I'd rather add than have to deal with too much of anything. I added CYA, acid and chlorine. I'll check it in 2 days and then fine tune the results. The Stenner appears to be operating properly, though it was dark when I turned it on.
 
I apparently ran the Stenner for too long over the past 1 1/2 days, so I cut down the injection to 1 quart per day and will check the levels again on Friday. Here are yesterday's test results:
FC = 9.2
CC = 0.2
pH = 7.9
drops to 7.4 = 3
TA = 155
CH = 190
CYA = 40 (may be lower, but I have difficulty reading this test)

I still haven't seen any signs of plaster dust, though there is some very light mottling forming in the deep end. Are the TA & CH acceptable, or should I raise them for the next few weeks?
 
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