Another cloudy water thread...can't seem to fix it

[jeremyp]

Dave,
Here is the current FC - 23ppm and CC - 0.5ppm. I'll recheck again late tonight and then again first thing tomorrow morning to see if the FC drops <1ppm and hopefully the CC goes to 0.

[jeremyp]

I just tested again and the FC is at 22ppm and the CC is at 0.5ppm. I'm not losing >1ppm FC, but my CC isn't 0 either. I brushed the sides and floor again for good measure. I'm assuming I should keep the current course of action...keep FC > 20ppm until CC - 0? Keep brushing sides and floor? What about adding DE to the sand filter...would that help at all?

[BigDave]

Sounds like you're there, 0.5 ppm is within the error of the 10ml sample test. Sounds like adding DE is the next logical step; be sure to check if it's blowing out the returns when you add it. BTW I haven't used the cellulose product you mentioned but I did try another last year and found that it didn't help and when I opened the filter I found it in large gray clumps on the sand.

[jeremyp]

Update:
I added some DE to the sand filter last night. (About 4 or 5 solo cups)
I back washed a few times prior so I had to add some fresh water. FC is now 16ppm, CC is now ZERO and pH is 7.4. The filter pressure climbed 11 psi and flow was pretty slow so I back washed again this afternoon. Results are still the same. This cloudy water isn't getting any better at all. It still looks exactly the same. How long should it take to see results from adding DE? Did I add enough DE, too much? This is starting to get a little frustrating to say the least.

[TheGoose]

Just for comparison sake, do you know how much sand your filter holds? Mine is rated for 325# and my starting pressure is ~20 psi.

You're only supposed to add enough DE for a ~1 psi pressure increase. I overshot mine also, but I found that if you shut the pump down for a few minutes and re-start the pressure somehow will come down. Mine went up to 26 on roughly one solo-size cup, but after I let it set for ~5 minutes it was back down to ~21 psi.

[jeremyp]

My Hayward sand filter holds 300 lbs +/- and clean filter pressure is 18-19 psi. After putting in the DE the pressure did rise 1-2 psi but after a half hour or so it had climbed another 5 psi or so.

[Watermom]

Too much DE. As you found out, it does take a little time before you see the total rise -- often as much as 20 or 30 minutes. So, cut way back next time.

[TheGoose]

Shut the pump down for ~5 minutes and see if it drops after you start it up. I think the loss of flow lets the DE get more evenly distributed over the top of the sand bed.