Changed my filter sand

[Theo]

As a part of my pool opening this year (5 year old pool, 2nd season owning it) I decided to pop the top of my sand filter and see how things looked. I've read that you should consider changing the sand after 5 years and I wanted to see the general condition of the filters internals.

The multi valve came off easily enough and the first thing I noticed was the fliter housing was about 1/2 full of sand and there were THOUSANDS of ants that had decided the sand filter was a great place to build their nest this year. I knew the ants would get washed out on backwash, but I had no idea if the sand was at the correct level. Other than that everything appeared normal.

I decided to vacuum out the ants then top it up with new sand. At that point I realized i had no way to measure the amount of sand I was removing so the decision was made to replace all of it. That turned out to be a decent decision; as I continued to vacuum the sand started to smell pretty awful. Then it got very awful towards the bottom of the filter - it smelled like cat poop, if that cat was on a strict blue cheese diet

I rinsed the entire filter housing and washed out the laterals then off to the pool store for 300lbs and ($57) worth of fresh filter sand.

I filled the filter about 1/2 way with water then replaced the laterals. I didn't have a cover for the tube that leads down to the laterals so I covered the hole with one hand and covered the tube with the other. I did about 2 of the 50lbs bags that way, then figured out I could rest the upopened bag on top of the filter then make a small slit in the bag, away from the tube. That process worked well, and I had more control over the distribution of the sand.

Once I had loaded all 300lbs I realized that filter was just over 3/4 of the way full w/ sand. The filter was approximatly missing approx 75 to 100lbs of sand before I stared. Everything went back together without issue. I set the valve to backwash and I fired up the pump. Backwashed for 3 min, rinsed for 1 min then backwashed for another 3min.

Before I started the pump on with the "Fliter" setting I noticed my pressure gauge was sitting @ 5psi. Time for a new pressure gauge

Everything fired right up, but I have no accurate way to judge if the nominal pool pressure is up or down. On average it operates around 22psi - I'm curious how the extra sand will effect the nominal pressure.

All around it was an easy process. I'm glad I got the ants and the funky smelling sand out of there. I think it was well worth the 2 hours of effort and $57 worth of sand.

 

[linen]

I've read that you should consider changing the sand after 5 years and I wanted to see the general condition of the filters internals.

The general consensus on here is that changing the sand is not normally necessary.

With that said, I think in your case it was worthwhile since your sand amount was a big unknown (and I am assuming you searched your filter's manual for a level and did not find it?). In addition, if you were not the orginal pool filter owner, you would not know if the sand was the proper sand or not. The "cat poop" smell should have gone away with proper chlorination.

How did the ant's get in there? You may want to "seal" up the filter next fall so this doesn't happen again. By seal, I mean block the places they could come in, without totally sealing filter where pressure could build up due to freezing (and of course doing a proper drain). Proper chlorination would have taken care of the ants as well

I'm curious how the extra sand will effect the nominal pressure.

Your clean pressure will go up a little, and of course, your filter should filter a little better. Get a new gauge, then do a good backwash to establish the new clean filter pressure.

 

[Theo]

The ants got in via the filter drain that was removed during the pool closing process. I could probably replace it a few weeks after I close the pool to prevent the ant infestation.

I determined the filter required 300lbs, but I had no way to measure what was already in there to determine if it was at the correct level. I'll be buying another gauge this afternoon. The current one is only a year old but at $15.99 it not a big deal.

 

[77shovelhead]

Being a new pool owner, and not knowing what was in my filter, I changed the sand last year. It's just that I wanted to know what's inside and that it was correct. Poured in the proper amount of sand and let it go. I only wish I had noted what the full mark was for later reference.