We have a Hayward 19" sand filter. We replaced the sand over the weekend. The standpipe was badly broken so I removed it from the lateral housing and replaced it with 1.5" PVC pipe. Inspected laterals and all looked fine, cleaned everything. We added water to the filter tank 1st, put the laterals in and slowly and gently started adding sand. We got a small bit of sand in and I realized we should make sure the height of our replacement pipe fit so we fit the multi-port valve on top but when we tried to pull it off the standpipe was really stuck to it so in the process of getting the valve back off to finish adding the and I think we lifted the lateral assembly up a bit. We felt inside through the sand and made sure it felt like it was in the bottom and then added the rest of the sand (total of 175 lbs. of 20# filter sand). We backwashed for a couple of minutes and rinsed for a minute or so. Turned on filter and lots of sand came in through the returns. I was thinking maybe we pulled the laterals up a bit or could it being seated to high in the filter cause sand to come back in? We took the new sand out and checked and the laterals were still folded down. Obviously the lateral housing and inside of them had sand in it. I cleaned it out and noticed a small crack in the top of the lateral housing where the pipe goes in. I put a good strong marine epoxy over that, let it cure and it's still shooting sand in. Could the housing be the problem? Should I just replace the whole lateral assembly? Had some trouble confirming EXACTLY how much sand to add. Can over or underfilling with sand cause it to come back in the returns? 
Second issue, I have been all over the internet and cannot find my model #. Hayward filter models seem to have a 3 digit number in the middle like 180 or 220, i.e. S220T but my model # is SM1915SHG. Perhaps that's a question best answered by Hayward.
Second issue, I have been all over the internet and cannot find my model #. Hayward filter models seem to have a 3 digit number in the middle like 180 or 220, i.e. S220T but my model # is SM1915SHG. Perhaps that's a question best answered by Hayward.
