Nothing if its a sand filter However if sand is coming into the pool from the filter then you may have to replace one ore more laterals in the sand filter as they have worn and are letting sand through to the pool,
Perhaps you have used the wrong sand or it is still blowing old sand out of the pipes.
how do you clean jacuzzi sand filter, and replace sand
distinguish between slow and rapid sand filter
Do you mean how do you install a sand filter?.
differentiate between slow and rapid sand filters
If you have a sand filter the laterals in it may be starting to show signs of wear these wil blow sand from the sand filter into the pool when they wear out.
Your filter will tell you on the side of it how much media sand to put in it.
If you are getting sand coming into the pool and have a sand filter you may have to replace worn laterals in the sand filter.
My Hayward sand filter doesn't have a liner. I just add the sand to the pressure vessel.
Im not an expert by any means but what I know is that with a sand filter system if your pump is not the corect HP for the filter it will push dibris and sand right back into the pool answer:: That may be true in remote cases where the system was not installed correctly or had well balanced/matched equipment. The correct answer would most likely be that you have a broken lateral(s) which allow sand to pass back to the pool. It is best to find the correct type lateral for your specific filter. Some manufacturers have made modifications to same model filters as production and technology progresses. Replacing the lateral required turning the equipment off and making sure it will not come back on while it is being worked on. Removing the filter top or valve assy. Removing all sand, finding the damaged lateral(s), replacing lateral, replacing the sand with new sand in the correct manner, replacing the valve or filter top and starting the equipment and backwashing the filter to reduce the dust blow back K
The filter might have been too strong for the gold fish to swim awa from, so it got sucked in
A 300-gallon filter? I have no clue. The industry rates filter on the diameter of the filter tank. So if you can cover the gallons to inches I can tell you how much sand you will need.