Hayward sand filter leaks

There is only one thing that can cause sand to come back into the pool from a sand filter. The internal assembly, called the lateral assembly, is either cracked or broken. This is an easy fix and should cost you around $70 to replace the whole thing. You need to unscrew the bottom drain cap on the filter to remove the water in the tank. Then, remove the multiport valve on top of the filter. Take a shop vac and remove the sand in the filter. If the sand hasn't been replaced in the last 3-5 years, this would be a great time to do that since you already have the sand out anyway. Then, remove the lateral assembly and inspect the entire thing. After you replace the lateral assembly, you'll need to fill the sand filter tank 1/2 full of water before adding fresh sand. This is done to cushion the laterals from the weight of the sand. Cover the hole in the top of the lateral assembly pipe with a cup or duct tape to prevent any sand from getting inside the pipe (the sand will come out into the pool if it gets into the pipe). Fill the tank 3/4 full of pool filter sand. Make sure it is genuine silica pool filter sand from a pool company. A lot of big box and home improvement stores sell play sand as filter sand. This will cause you more problems!

A Hayward S180T sand filter holds 150# of sand. In other words, fill the filter 3/4 full of sand (to the point where the tank starts to round off). Make sure, however, that you fill the tank 1/2 full of water first. This will help to cushion the laterals and prevent them from breaking from the weight of the sand. Make sure to cover the hole in the top of the lateral assembly pipe with a cup or duct tape to prevent sand from going into the pipe. If sand gets into the pipe, it will come out into the pool. Don't forget to remove the cup or tape after adding the sand!

They are fiberglass ... fiberglass repair kit should do it ...

Im not so sure I would fix it ... if it is broken ... there are probably problems you cannot see ... might be cheaper to replace the tank when you consider what might happen if it breaks while you are not around.

I am not that familiar with the G series Hayward filters, but most sand filter tanks do not separate. It's a labor intensive job so think hard before trying it if you haven't before. If your backwash valve is on top of the filter, the plumbing will have to be removed. There are two ways that I have removed the sand. Scooping it out by hand or using a shop vac. Remember the sand is going to be very heavy when wet. You will need to go through the top. Some filters have a large drain plug in the bottom that "supposedly" you can drain the sand out through.I have done this once and it makes a big mess that you still need to clean up.

Be sure to buy replacement o-rings and gaskets as needed. There is also a product called a sand vac that is in essence a siphoning system.

Be careful not to damage the laterals it the bottom of the filter. When replacing the sand, I put small gravel (pea gravel) carefully under and partially around the laterals to help support them from the weight of the new sand.

When you are done, be sure to backwash the new sand to remove dirt, impurities, etc. This is a general overview. There are books online that give more detail or use a similar filter's manual...

those tanks are designed to hold alot of pressure. If it is cracked, it's already unsafe. When the pump turns on, the tanks usually flex a little bit, depending on your system. The flexing usually makes the patch come undone. It's best, and safer, to replace the filter tank.

I don't think you can buy just the filter tank. Most places only sell the filter tank w/skirt, drain & lateral assembly as a single unit. If the crack is more than an inch or two long I would not risk repairing it as there can be upwards of 30psi when the filter is dirty (safety issue). You can try some epoxy on it if its a very small leak but the success rate for that kind of repair is not very good.

O-rings or gasket are replaced to stop leaks, so that wouldn't have helped you.

It could be one of two things; either the white PCV-like pipe in the filter tank is cracked OR some of the laterals at the very bottom of the tank, under the sand, has melted. A whole new underdrain assembly is usually $70.

Most hayward sand filters use a GMX600F or GMX600F-H o-ring.
If it is an older tank it might use the GMX400F which is smaller, and rare to come across. Most 400 Valves are not marked vari-flo.

Hope it helps.

if leak is around the top 7-way valve it is probably the rubber o-ring underneath that needs replacing. if the tank itself has a crack or hole you could try something like j/b weld to patch the hole.