The best way to drain water out of a pool is through a 1 1/2" waste line. If you have a filter with a multiport valve, you probably have this feature built in as one of the valve mode. But if you have a cartridge filter you may not have this feature and you may be spending hours draining your pool with a garden hose. This guide shows you how to add a valve and 1 1/2" hose to drain your pool.
To add a larger waste hose we will have to T fitting into a stretch of pipe on the discharge side of the pump. Ideally we will want a place next to a union so that we can remove a section of pipe and provide room to slip in a T fitting. The best place appears to be the section of 2" pipe coming off the heater union.
Because we are going from 2" pipe to a standard 1 1/2" hose, you will have to use a 2" to 1 1/2" T fitting.
Adding the T fitting will make the length of pipe going to the union longer so we will have to shorten this pipe. To determine how much to cut off, measure the inside of the T fitting between the two stop ridges. The measurement for this T fitting is 2". Add 1/4" to this to allow for none square cuts. Note: not all T fitting are the same size so measure the T fitting you purchase.
Immediately push the T fitting onto the 2" pipe and twist 1/4 turn to spread the glue. Make sure the T fitting is lined up in the correct direction. It may help to side a 1 1/2" pipe into that side of the fitting to see where it's going before gluing the fitting. Wait 30 seconds for the glue to set.
Deburr and clean the 2" pipe
Slide the loose pipe into the T fitting to check the length of pipe fits to the heater union.
Cut and deburr a length of 1 1/2" pipe that will get us past the other pipes
Wait 2 hours for the glue to completely dry.
Open the ball valve.