D.E. & filter help needed

[delfargo]

i started talking about this in a discussion about floc in the b.b.b. forum. the floc discussion was done, so i figured i'd start a new topic to figure out this D.E. situation i have going. my numbers seem within reason, but i can't seem to get the water crystal clear. i floc'ed the pool, vacumed to waste and it was clear as a bell. 2 days later, it's cloudy. not green, but real cloudy. so i floc'ed again, same thing. so i was advised that perhaps my filter was to blame and i should add d.e. to my sand filter. so now we are on the topic of d.e. here are last nights numbers (i didn't have time to test this morning, as i had to get to work)-
fc-18 (i'm keeping it at shock till this cloudiness clears up)
cc-0
ph-7.3-ish (kinda in between the colors on the tester)
ta-350 (yeah-way high-and i've done this test several times to make sure i didn't screw it up)
ch-150
cya-45
through trial & error i've determined that just a little over a 1/2 cup of d.e. ups my filter pressue from 18 (where it runs when clean) to 19 in about 10 minutes, which is what i was advised to do. checked about an hour later and it was at 20 with hardly any flow coming out the return. so before bed last night i backwashed the d.e. out and repeated the d.e. process. this morning the pressure was back to 20 with little flow from the return. the water looked a little clearer. so here's the part that confuses me. usually when i backwash, the water coming out of the waste hose turns really ugly and dirty and then goes back to normal, so i know i've filtered out alot of gunk. when i backwashed this morning the waste was not as"yucky" as usual. i would have figured that, with the extra filtering the d.e. is supposed to be giving me, it would look dirtier than usual, not LESS dirty. am i doing something wrong? should the pressure creep up that fast? also...how often should i backwash doing this d.e. thing? any ideas?
thanx, oh gurus of the pool, for your help.

 

[Hotrod30]

Just a couple of questions.

What size pump do you have?

What size sand filter do you have?

Have you always had 18 lbs pressure when your filter was clean?

How many hours a day does the pump run?

 

[delfargo]

ah yes...of course. silly me. no, i don't have the pump / filter info. in front of me. i'll have it for y'all tomorrow a.m., (i don't have a computer at home, only here at work) but the pool place that sold me the pool said it was the right size for the 30' round. yeah, it's always been around 17 / 18 when it's clean. i used to run the pump about 12 hrs. a day, but this year i've been running it 24/7 cuz i've been having such a hard time keeping it clear.

 

[Guest]

ta-350 (yeah-way high-and i've done this test several times to make sure i didn't screw it up)
ch-150

This is a very possible cause of your cloudiness!
Work on getting the TA down.
Drop your pH to 7.0 and see if any of the cloudiness clears. IF it does then you have calcium precipitating out and you need to get your TA down!

 

[delfargo]

thanx guys. 'bear... couple of questions: can you get bad acid? (not the brown acid at woodstock, but bad muriatic acid)? i had to use a whole gallon of the stuff to drop my ph from 7.8 to where it is now, and i know it shouldn't have taken that much. and also..the only way i can think to aerate the water to try to get the t.a. down is to aim my return "eyeball" up to create bubbles. but won't not having my return aiming down & to the right lessen the movement of the water and the abilty to filter out my cloud? kind of a catch 22. i thought my ch was at a good level. am i reading the "recommended levels" wrong? thanx again.

 

[jugger2500]

We will see what waterbear says when he returns. However, I believe he was indicating that the TA and the CH coupled together could be the cause of the cloudiness. And as such he was suggesting bringing the TA down. I think he is indicating that a lower TA but the same CH would probably be fine and not as likely to have the clouding issue.... Does that make more sense?