How do I diagnosis channeling in the sand filter?

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queenofmyswamp

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Jun 8, 2008
114
I have been running the filter like crazy and just have this cloudy haze (the pool is a beautiful, but opaque aqua color) that only allows me to see about a foot down. when I put the water in a clear glass, I can see lots of tiny white floaties (dead algae I assume) but we aren't making progress with the cloudiness. Test numbers are all good. Also, I have not backwashed the filter in probably 6 days, which seems unusual if it is doing its job.

So....do I drain the filter down and just unscrew the mult-port valve and look in? Will I be able to easily tell by looking in if I have a channeling problem? This is, I think, our 4th season with this sand filter and we bought it new. I am not sure if it should be due for any maintenance by now, but we haven't done anything with it really since buying it.

Any help appreciated!

Thanks.
 
Okay - thanks - I just read the info at that link. So I am not needing to drain the filter, just put a hose in and let it overflow, right? The pressure has increased to where I backwashed it the morning just a few minutes ago, but based on my past experience, when the pool has been super cloudy like this, it needed backwashed fairly often, whereas this past week or 2, it has not increased in pressure quickly at all, and has not cleared up.

Lastly, I don't know if this means anything, but usually with a clean filter, the PSI is about 9, and after I just backwashed it here a few min ago, it only went down to about 12. Does this mean anything?

Thanks for the quick help! I am hoping to get something done before I leave for church this morning and my husband said, "you aren't going to get an answer quickly on a Sunday morning!" I said, "watch me ~ this listserv is great!" So, thanks for helping prove me right? LOL
 
One other thing I just noticed that has been happening on and off the past few weeks and is right now after a backwash, the return jet is sending a lot of bubbles back into the pool - tiny ones like you would see in a hot tub return. ????
 
Test results:

Chlorine: 11
cc: o
alk: 160
pH: 7.2 - a little low, but thinking that with all the bubbles from the return jet, this may go up on its own?
calcium: 170 (first time I have tested this, so not sure what that means?)
CYA: <30 - have been keeping this purposely low until cleared (have some dissolving in pool for past week) because I have been buying so much bleach, I didn't want to have to have it at super high levels and buy even more - will raise it once get pool clear

passing OCLT

Have been holding chlorine level high for days and just can't get past this milky stage. HELP!!! :(
 
It sounds like you have grasped the fundamentals of pool chemistry!

It also sounds like you have an idea of what to do with the sand. So poke the hose around in there and keep us posted.

I'd look at circulation. AG pools don't usually have a floor drain, so the filter intake and return are all fairly high up the wall. The top of the pool gets good circulation, but maybe not so much down lower. Is there any way to point the return down?
 

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A week and a half ago, I added clarifier, which didn't help. I then added floc and let it sit overnight. Still no difference. When I turned off the filter after adding floc, I put a glass of the milky water on my windowsill. About 3 days later, there was lots of sediment on the bottom of the glass, so I assume the floc needs a lot more time to work, but I am concerned about my pool not being stirred up for 3 days and chlorine level dropping.
 
My advice at this point is to try something and allow it time to work. My preference would be to stir up the sand in the filter to be sure it isn't channeled and aim the returns down so you get all the crud stirred up to where it can get grabbed and filtered. See what it looks like in 24 hours.

You might put a yardstick in the pool, or use the ladder or something as a gauge so you can actually measure the visibility.
 
Okay, thanks for the suggestions. I have been using the steps as my measuring guide, and can see the first step fairly well, and just a shadow of the second one. We will try the hose in filter thing this afternoon and see if we get any results from that. I suppose I won't really be able to tell much today as far as whether there is channeling, but will just see if things start to clear up and will be able to assume that was the problem. ??
 
Okay, forgive me, but I have one last question....hubby doesn't particularly want to take the filter apart and suggested another possible issue and I thought I would run it by you pool experts to see if you think this is even possibly my problem. Last year, we put in what I think are called "wedding cake" steps. It is anchored down with quite a few 50 lb bags of sand. My husband is wondering if lack of water flow through that area could be causing the water to be cloudy? Any thoughts appreciated. Thanks!!
 
nope - they are just bags laying under there. Well, I guess it is good that I may have found the problem! Now to get the kids in there to help get them out. Not sure what to do with them once they are out, however....?

Is is possible that they could make the water cloudy even though my chlorine level is stable?

sorry for so many questions, but I REALLY appreciate the help!! Party here this coming weekend and I really want clear water!
 
Like I mentioned above, the pressure has not been increasing like I would expect considering how cloudy the water is. Until today, I hadn't backwashed in probably pushing 6 days or so.

Update: hubby and I and the kids got the bags of sand out and stirred up a swamp in the recesses of the steps. Scooped buckets of the green water out of it and then lifted it out. I am pretty confident that was our issue ~ I can't believe how stinky and green it was! Feeling stupid that I didn't think of this issue sooner. I just added a bunch of bleach and am going to go back to shocking and hopefully this will take care of the issue and it will be clear for this coming weekend!!

Thanks again for all the input - I will keep you updated on our progress in case anyone cares.
 
Good morning! Okay, here are my crazy results: I raised chlorine level to 21 last night before going to bed (.5 cc) and this morning, both numbers are exactly the same. Filter ran all night, but absolutely no progress at all as far as clearing the milkiness. Is it just too soon to expect a change? I am going to check the filter pressure, but it appears to still have good return flow just from looking at the water. I am really confused as to why the chlorine level wouldn't have gone down significantly with all the algae we stirred up in there - there were some clumps of mossy looking stuff that we broke loose from the back of the steps that were floating around last night.

Thoughts appreciated. Thanks!!
 

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