what size sand filter for 15x30 pool

[farefax]

Hi wondering if anyone could point me in right direction, I have a 15x30 pool with an AA in floor cleaning system I just bought the house it has a 1 hp Hayward pump which doesn't seem to be working well , if I open the valve for just the skimmer it moves the water to skimmer basket OK, if I switch it to floor vent it draws in water OK as well but if I place it to do both there is no movement of water in skimmer basket. It has a Hayward cartridge filter about 4 foot tall I have cleaned filter several times and doesn't make a difference. I have a pressure meter and it is reading about 30 so I don't know if why it doesn't work when I switch it to both vents Cant find any numbers on it. I am planning on adding solar heat to it so I will need to replace pump was also thinking of replacing cartridge filter to sand filter, not sure if there is something wrong with my pump but figured I have to change it anyway to add solar panels to it. Any help on pump size I should be looking at? :?: Any help would be appreciated.
Thanks
Larry

 

[JasonLion]

You may not need to replace the pump, it depends on how many, how high up, and how far away the solar panels will be and if you want to be able to run the solar and the in floor cleaning system at the same time. In floor cleaning tends to require slightly higher pressure, while solar usually works better with slightly lower pressure, so there are some advantages to splitting the system. That could be done either with one pump and automated valves or two pumps. The plumbing issues can get kind of complex, if you are going to have someone else do the solar have them figure it out. If you are doing it your self you will need to get a lot more specific about how many panels how high up, what size pipe, what distance, etc.

The skimmer vs floor vent issue sounds like you simply need to find the right position for the valve(s) to balance things out the way you want.