I've got a sand dollar filter that seems to be putting sand in the pool. It seems like everything I'm seeing says it's a spider gasket. Does anyone have any advice before I pull the valve apart to replace the gasket? Thanks.
Sand filter putting sand in pool
- Thread starter jde2
- Start date
There's not really any reason sand should be passing through the spider gasket unless it's happening on backwash, and even then it wouldn't be much. How much sand is coming back in?
Enough is coming through that it spots up all over the bottom of the pool. For the past two years I thought it was mustard algae, I've spent hundreds of dollars on algae killer. Yesterday I took the winter cover off, nothing in the bottom of the pool, cranked up the pump and within 30 minutes I had the spots all over the bottom of the pool. I've come to the conclusion that it is sand being put in from the filter because I didn't have anything there until I cranked up the pump.
Welcome to TFP!!
To see if it's sand, you can either reach down to the bottom and collect a sample and see if it's sand or, if you don't have 4' long arms (
) attach a nylon knee-high to one of the returns to catch stuff coming out and inspect the contents (turn the pump off and on a few times over a 10 minute period, more stuff comes out when the system first kicks on) 
Do a little experimenting to see what the stuff is and we'll help you from there
To see if it's sand, you can either reach down to the bottom and collect a sample and see if it's sand or, if you don't have 4' long arms (
) attach a nylon knee-high to one of the returns to catch stuff coming out and inspect the contents (turn the pump off and on a few times over a 10 minute period, more stuff comes out when the system first kicks on) Do a little experimenting to see what the stuff is and we'll help you from there
How well is your backwashing working?
Have you stirred your sand?
Could be the spider gasket.
Could be clogged sand.
Have you stirred your sand?
Could be the spider gasket.
Could be clogged sand.
it could be a broken lateral...it does happen on sand filters...if you can get a sample you'll know it's sand if it is gritty...sand in filters is pretty coarse vs. fine dust that usually settles to the bottom
I just put new sand in the filter. None of the laterals were broken. I haven't had a chance to look and see what it is yet.
Did you backwash and rinse the filter after adding the new sand? If not, that could be the problem and it's done doing that now
Bob_Funk
0
I had the same problem, new sand, good laterals, replaced the spider gasket-still sand in the pool.
I took all the sand out AGAIN & dis-assembled the the whole lateral arm & there was a huge crack on the bottom of the piece that the laterals screw into.
I would never have seen it if I had not taken the whole thing apart.
The filter is old & 1st pool co. said can't get the part buy a new filter
2nd pool co. couldn't find the part either but had a piece that my laterals would screw into & gave me 2 90 degree elbows & I was back in business for $17
I went with option 2
Bob
I took all the sand out AGAIN & dis-assembled the the whole lateral arm & there was a huge crack on the bottom of the piece that the laterals screw into.
I would never have seen it if I had not taken the whole thing apart.
The filter is old & 1st pool co. said can't get the part buy a new filter
2nd pool co. couldn't find the part either but had a piece that my laterals would screw into & gave me 2 90 degree elbows & I was back in business for $17
I went with option 2
Bob
I put on some goggles and went to the bottom and felt it, it's gritty like sand. I guess I'll start with the spider gasket.
jde2 said:
From what I've seen people sometimes confuse dead algae for sand, usually if a cracked lateral is to blame and sand starts shooting out the return line it doesn't end up very far into the pool. The sand is so heavy is makes it only a foot or so and piles up on the floor. To make sure it is sand brush it, if it moves it is sand; if it fluffs up and disappears it's not sand.
It does puff up and disappear. It feels gritty like sand. If it's dead algae, why can't I get rid of it? I've changed the sand a couple of times. I've put in every kind of algae killer there is, the spots keep coming back year after year.
I can try and take a picture but you probably won't be able to see it clearly. Basically, it's brown spots all over the bottom of the pool. I can brush the bottom of the pool and by the next day the're back, the longer I let it go without brushing the more spots I get. I rubbed it between my fingers and it feels like very fine sand or dirt. I'm at a loss. I've changed the sand 3 times and put hundreds of dollars worth of algae killer in it in past years. It didn't appear this year until after I took off the winter cover and turned on the pump. Before I turned on the pump, there was nothing, that's what made me think it was sand.
Sand, dirt, dust...dead algae, any of the above. Performing an overnight FC test can confirm if the substance is organics - or just pollen/dust/sand.
I have it too, and I know it's not any form of algae, because my FC holds. And I have a cartridge filter....
Sand filters can be tricky that way - did you try the kneehigh over the return to see what's getting thru the filter, if the filter is the issue?
(sounds like a slight case of sparklypoolitis to me....
:lol: )
I have it too, and I know it's not any form of algae, because my FC holds. And I have a cartridge filter....
Sand filters can be tricky that way - did you try the kneehigh over the return to see what's getting thru the filter, if the filter is the issue?
(sounds like a slight case of sparklypoolitis to me....
:lol: )
jde2 said:
I re-read your description of your problem it actually sounds like mustard or yellow algae. I recently used Yellow Treat from united chemical and it works very well. If the brown grittiness is coming back in the same spot day after day I would think it's definitely mustard/yellow algae.
frustratedpoolmom said:Sand, dirt, dust...dead algae, any of the above. Performing an overnight FC test can confirm if the substance is organics - or just pollen/dust/sand.
I have it too, and I know it's not any form of algae, because my FC holds. And I have a cartridge filter....
Sand filters can be tricky that way - did you try the kneehigh over the return to see what's getting thru the filter, if the filter is the issue?
(sounds like a slight case of sparklypoolitis to me....
My mother-in-laws pool had deposits of brown and her chlorine was holding just fine so I thought it wasn't algae either but the yellow treat I tried actually improved the pool, the brown went away and the deposits became fewer and lighter in color from a dark brown to a light tan or grey.