Pool filters can leak from a number of places and depending on where they are leaking from will determine how much and how long it will take to repair the leak on the pool filter. The first thing you will need to do is find out where the pool filter is leaking from. Once you find the leak and you are sure that is where the filter is leaking from you can fix the leak and save water.
My Pool Filter Is Leaking

My Pool Water Is Leaking Out Of The Back Wash Line:

When the spider gasket inside of the multiport goes bad water will leak out of the back wash line or port. This can cost you a lot of money is wasted water so its best to get this fixed right away. To fix a leaking multiport on your swimming pool filter you can either replace the spider gasket inside if the body of the multiport is good or you can simple replace the entire multiport.

My Filter Tank Is Cracked, How Can I Repair It?

Often when the pool is closed for the winter some pool filters are left outside with water in them.During the winter season the temperature goes below freezing and will crack the pool filter tank. If the crack in the tank is on the smaller side you sometimes can repair the tank with some two part epoxy. You will have to keep in mind that a swimming pool filter is pressurized and if the crack is to large in size you will just have to replace the broken part of the tank. Most pool filters have different sections of the tank and replacement parts are available instead of buying a whole new complete filter. For instance if you have a cracked Hayward Microclear, swimclear, Perflex and you are having no luck repairing the tank you can just buy the replacement upper or lower tank.

My Fittings Are Leaking On The Pool Filter Tank:

If the fittings that screw into the multiport on your filter tank are leaking then you will need to back them out and apply new Teflon Tape and thread sealant to them. Placing goop or silicon on the outside of the threads will not stop the leak. You will have to remove the fittings.