Removing Fine Dirt From Dirty Salt

smthomas7 · Jun 28, 2018

A week or two ago I added a bag of salt and didn’t notice it was a bad (really dirty) bag of salt till most was already in the pool. It made the water cloudy, but a lot settled out in the bottom of the pool over the few days it wasn’t used. I manual vacuumed, but the particles are so fine they seem to be going right through my cartridge filter and I keep having the same issue over again. Unfortunately, I had cleaned the cartridge filter shortly before this issue, so that could be part of the problem (no dirt in it already to increase performance...had to get all the worm guts out from opening in May).

Any ideas of how I can get my water clear again without waiting for the filtration to get better by itself over time as the filter gets dirtier? Any filter aids that can be used with cartridge filter? I have a large filter that really only needs cleaned once a year, so it takes awhile to even build up any head loss. I can’t vacuum to waste unless I add a bypass valve to my piping and not sure how much water I would suck out and need to replace with more water and salt.

Thanks.

Richard320 · Jun 28, 2018

Any filter should be able to filter out stuff large enough to see with the naked eye. If you vacuum up dust and it blows back into the pool, there is something wrong with your filter. Something not seated properly, maybe? A small tear?

smthomas7 · Jun 28, 2018

Richard320 said:
Any filter should be able to filter out stuff large enough to see with the naked eye. If you vacuum up dust and it blows back into the pool, there is something wrong with your filter. Something not seated properly, maybe? A small tear?

I thought the same thing possibly, so I going to check it. However, I am careful to inspect any time I clean and make sure the gaskets are all in place for proper seating. Also, headloss appears to be the same as it always is, so any hole or leak path would have to be pretty small. Finally, even the filter manual states that small particles may pass when the filter is clean. In a later section it says colloidal particals may pass through and to vacuum to waste if they have already settled or use alum to coagulate. However, it doesn’t say if I still need to vacuum to waste if I use alum or if I can just vacuum through the filter. The particles are very small like colloidal particles as they take days to settle and you can’t see them till they settle except the cloudiness they create. My filter elements are going on about 4 years old, so they probably aren’t filtering as well as new until they build up some dirt coating.

smthomas7 · Jun 29, 2018

I am now wondering if I have a mustard algae problem instead of dirt and it was just cooncidence I had dumped some dirty salt in a day or two before this issue. I have read older threads where it seems some types of mustard algae can appear to be dirt that settled on the bottom of the pool. Its just hard to beleive as my chlorine demand seems normal and it can be removed very easily as doesn’t seem to be attched to the pool. Its like dust.

Going to try bumping up chlorine which is currently 6 (salt pool). All other levels in accordance with TFP methods.

Anyone else have any experience with this?

mknauss · Jun 29, 2018

Do a Overnight Chlorine Loss Test tonight. It will tell you if you have an organics in the water.

How does your water look?

smthomas7 · Jun 29, 2018

I had the cover on for the last 1-1/2 days and when I opened it looked cloudy...about the same as the day I vacuumed and put the cover back on. On that day and prior days when I checked it, the water seemed pretty clear and the “dirt” was on the bottom. It only got cloudy after I vacuumed through the filter and that is why I thought I had a filtration problem.

I was expecting to see the “dirt” on the bottom again today, but there was very little. I set the SWG to 100% and turned up the pump about 2 hours ago. It already looks much better than it did in just this short amount of time. Maybe I have been teeter tottering on a full blown algae outbreak. If it keeps clearing up with more chlorine, I guess I would need to do a SLAM to try to knock it out. I will also do an overnight test as you said.

smthomas7 · Jul 1, 2018

FYI...for anyone that was following this. I did overnight chlorine loss test and didn’t have any loss. However, since I was still at a loss as to the cause of my cloudy water, I still raised the chlorine level to about 3/4 of shock level (still wanted to swim as this is the hottest weather we have had this year). Pool was still cloudy yesterday after 24+ hours. Went and bought some cellulose fiber media which is supposed to be ok for cartidge filters. I only put a few cups in (much less than directions on bag) to try to close up any pores in the filter as I had recently cleaned it. Today the water already looks better...not 100% yet, but it started to get the sparkle back and you can see the bottom much better.

Still not 100% sure, but I think all my issues were due to a clean filter and very fine dirt from the bad bag of salt I used. Lesson learned to inspect the salt before I dump it in!