Cyanuric Acid

[aylad]

It is not normal for the DE to blow into the pool. Did you add it slowly through the skimmer? It should have gone in and coated the sand but not gone through it. How long has it been since you backwashed the filter? Sounds like maybe the sand in your filter is "channeling"--that sometimes happens with very old sand or with a pump that is too big for the filter, where it creates channels in the sand. That might explain why it's not filtering the "brown stuff" out to begin with. Have you checked to see if the "brown stuff" is gritty, maybe it's sand blowing back into the pool?

If you haven't backwashed lately, go ahead and backwash well, then rinse well, then put it back to filter and try a little more DE. I think I'd start with about 1/3-1/2 cup, though, just in case it blows through. If it blows through this time after backwashing, then you've got filter issues that need to be resolved.

Janet

[Sue225]

I have suspected, since I subscribed to this forum, that our pump is too powerful for our filter. 1 1/2 HP pump for Silica I filter. 24 round UG pool! Our pressure never goes up and very little dirty water is backwashed out. Of course, my husband doesn't want to hear it but I am pretty sure this is the problem. The brown stuff is definately not gritty.
We replace the sand every summer. At the end of the season it is white as snow, normal?
Your thoughts appreciated

[CarlD]

Why do you replace the sand? I never do and neither do any of the mods. I'm in my 8th season and Al is in season 13 or 14 with his sand. I suspect it's white from being agitated too much by too big a pump for it.

I suggest you get a bigger sand filter. Performance will improve and you'll not need to replace the sand.

[aylad]

I agree with Carl, you shouldn't have to replace the sand. I've replaced mine once in 8 years, but that's because I got a new filter and changed over to Zeolite. Otherwise, there's no need to change it out unless you're converting from a Baquacil pool. I think that a 1 1/2 HP pump is definitely overkill for your pool, and probably is making your filter very ineffective. I strongly encourage you to get either a smaller pump or a larger filter.

Janet

[Sue225]

We have always replaced the sand for no apparent reason. We just thought you were supposed to replace it for efficiency.
I think someone (pool store) told us that a bigger pump would cut down on the time for running filter! We never questioned it. Will definately talk to husband about replacing for next summer.
We are in NW indiana and have only about 1 more month of swimming then grandkids go back to school and no one will use it for the next month (at least that is the way past summers have went). We usually cover pool by mid Sept. Maybe this year we will wait until leaves start falling in Oct.

[aylad]

I think someone (pool store) told us that a bigger pump would cut down on the time for running filter!

It's easy to forget that the pump turns the water over--it's the filter that actually cleans the stuff out of the water. Granted, a bigger pump may turn it over faster, but if the filter can't handle the load, then it's defeating the purpose (and actually more expensive) to have the bigger pump.

Janet

[Sue225]

This would explain why my water is clear but a different color blue. I am using a skimmer sock until we can replace filter or pump. Amazing how much crud the sock filters out. Problem is I have to clean it every couple of hours or so. I am noticing some gritty dirt (sand) in the sock. I'm thinking the filtration has been the problem all along.
Would the filter be throwing off sand?

[Watermom]

If the pump is too powerful, it can force stuff right through the filter and into the pool. Over time, it will also damage the filter.