Time to Take My Pool Back from Leslie's

[pentachris]

Actually, with a sand filter, if you'll remove any chemicals or tabs from your skimmer, you can LOWER your CH by adding the cal hypo via the skimmer. You must be 100% certain that there are no OTHER chemicals the cal hypo will contact, before you do this! And do it cautiously -- small doses -- at first, to make sure the calcium doesn't blow through your filter.

Other chemicals such as what? How would I tell?

[PoolDoc]

Other chemicals such as what? How would I tell?

skimmer tabs

. . . or ANYTHING else. Basically, your skimmer needs to be clean and empty of anything except pool water, when you add cal hypo. AND, you must NOT have a feeder of any kind between the skimmer and the filter. (Downstream of the filter is OK.)

[pentachris]

Ah, I see. I thought you were referring to other chemicals dissolved in the pool water.

I'll keep it sanitized with the cal-hypo for now, going through the skimmer slowly and watching the outlets for blow-through. Maybe it will tell me on the pail, but does anyone know what the dosage rate is (X ounces will increase Y gallons of water by Z ppm free chlorine or whatever)? It's 73%.

My wife has a Sam's membership with her employer, so we'll make time soon to go get some dichlor.

I'll post back here with updates/questions.

Thanks again.

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Never mind my dosage question. I came home for lunch and found the answer on the bucket. X=1, Y=5000, Z=1.

I slowly added 12 oz through the skimmer closer to the filter and did not notice any blow-through.

I am starting to see a tinge of yellow around the edges.

I'll test, add more cal-hypo if necessary to get to 5 ppm and brush well this evening.

[pentachris]

Sample taken at dusk (87.0 degrees F, just for grins and giggles), showed 1.2 ppm FC. I added 16 oz of cal-hypo, waited an hour, and tested to confirm that I'd raised it by the desired ~ 4 ppm. It came in at 5.4 ppm.

I also brushed it well at about 5:30.

You know, if I'd just gotten rid of the dead algae to begin with, paid attention to the instructions on the cal-hypo bucket, and used that to sanitize the whole time, I probably wouldn't be in this mess. Imagine that - read the instructions! :/

[PoolDoc]

You know, if I'd just gotten rid of the dead algae to begin with, paid attention to the instructions on the cal-hypo bucket, and used that to sanitize the whole time, I probably wouldn't be in this mess. Imagine that - read the instructions! :/

Not quite.

If you follow the instructions on the bucket, you'll eventually end up with massive calcium levels over time. Adding via the skimmer will avoid that, but the companies aren't going to explain, because of the hazard if you put cal hypo in skimmer that has a trichlor tab or something else in it.

[pentachris]

Tested this evening at 0.8 ppm FC, 0.2 ppm CC.

I added 16 oz of cal-hypo again, and this time I noticed that the water coming out of the outlet was cloudy. I'm guessing that's the blow-through, and I'll need to replace the filter sand. With the pipe cutting required, and the advantage of installing unions as was previously mentioned, I'm thinking I'll probably hire this job out.

[PoolDoc]

I'm guessing that's the blow-through

Don't jump to that conclusion. Not all of the calcium in cal hypo is insolubles that can be filtered. To actually test your filter, get couple of pounds of DE powder, and put THAT in your skimmer (it won't react with cal hypo). If the DE blows through, it's a filter problem. Otherwise not.

Your CH level is so high, the soluble portion of cal hypo can still trigger some precipitation, visible as cloudiness.

ALSO, a sand filter will not grab the cal hypo insolubles well just after it's backwashed. When using cal hypo this way, you want to back wash as much as you have to -- 7 - 10 psi pressure rise, but no more than that.