Time to Take My Pool Back from Leslie's

[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.

[pentachris]

Makes sense. Speaking of which...

Should I be seeing pressure rise as I'm removing CH from the water? My pressure has been pretty constant for several days. How does adding cal-hypo to the skimmer remove CH from the water?

[PoolDoc]

You precipitate it out on your filter, instead of onto the bottom of your pool. You'll know it's working, if your backwash is sludgy, thick, and kind of a grayish tan.

[pentachris]

Yesterday morning, I vacuumed the pool. I saw a fair amount of dead algae blowing through, but I just wanted to get it decent for the get-together my wife hosted yesterday afternoon. I was obviously filtering at least some of it though, because when I was done the pressure had risen by about 9 PSI. So, I backwashed and rinsed.

The water was cloudy for the party, but it went over well. So, now I'm over the short term hurdle, and ready to do what needs to be done to solve problems long term.

I bought some DE powder today. I put 2 cups in the skimmer, and about 15-30 seconds later, there were plumes of white pouring from the outlets. I also tested the CH level today, and it measured ~800.

So, regarding the filter: Is it worth it to try the "sand revitalizer" stuff? Is it worth it to put a cup or two of Fiber Clear in after every backwash and see if that forms a filter on top of the sand? Or should I bite the bullet and plan to replace the sand? (If I cut the PVC pipes to open the filter, it makes sense to me to go ahead and replace the sand, regardless of any other tricks there might be to get it filtering properly after I get the valve removed. I don't know if there are any, I'm just saying that I think it would be silly to remove the valve and not replace the sand.)

Regarding the water chemistry: I got 24# of dichlor from Sam's. Should I go ahead and switch from cal-hypo in the skimmer to that? Should I wait until I get the filter problem resolved first? I'm guessing if I need to replace the sand, it'll be at least a week before that gets done. Like I mentioned before, that's a job I'll probably hire out because of the plumbing involved.

Thanks!

[pentachris]

It's now about 4 hours after putting the DE powder in my filter. The pressure has increased about 5 PSI, WAY more than it normally does in that short of a time period. Just throwing that out there as another bit of information that might be relevant.

[PoolDoc]

I bought some DE powder today. I put 2 cups in the skimmer, and about 15-30 seconds later, there were plumes of white pouring from the outlets. I also tested the CH level today, and it measured ~800.

So, regarding the filter: Is it worth it to try the "sand revitalizer" stuff?

If DE blows through the filter, I can think of 3 possible causes:

1. There's not enough sand OR it's not filter sand (too coarse).

2. There are CHANNELS in the sand, that allow the water to bypass most of the sand -- can happen if the sand gets gummed up.

3. There is something wrong with the structure of the filter; in the case of DE bypassing, a misplaced air relief line can do it.


BUT . . . all of these problems can only be fixed by opening the filter.