The setting of the sand filter should be on filter for a normal vacuum. However if you are getting rid of the results of using clarifier from the bottom of the pool you would be beter of vacuuming to waste.
For the first cleaning in spring set it to "waste" while vacuuming. Subsequently you can leave it on "filter" when vacuuming.
Just keep the setting on filter you may find that the preasure increases and if it does just give it a quick backwash to reduce it if needed.
check your filter it might need to be replaced.
You have one or more bad filter elements inside the filter. The filter needs to be serviced .
You have two options when vacuuming a pool. If it a normal weekly vacuume you will set your filter valve to the filter position. This will send the water through the filter and back to the pool. Once your done vacuuming, you then backwash and rinse the filter. A good ratio is 3 min to back wash and 30 seconds to rinse. If your pool is extremely dirty like at the begining of the year, You can sometimes set the filter to the waste position. This will bypass the filter and send the water down the backwash line. This lowers the water in the pool. If your pool is extremely dirty and you try to vacuum with it set to filter, the filter will not catch all the dirt and some will end up back in the pool in the form of dirty or cloudy water. As a pool profesional I always strived for clear water first. You can't clean what you can't see.
Cartridge is not installed correctly or you have a crack in the manifold allowing dirty water to pass by the filter.
Possibly because it is set on circulate and not on filter or if you have a cartridge filter the cartridge is damaged. Worn laterals in the sand filter can also cause sand to blow back into the pool.
If you're talking about your pool filter, it should be set to filter or run. Use the bypass or recirculate setting if you wish to circulate the water without having the water pass through the filter. Use the backwash setting to clean the filter.
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.
Probably because it is clean, leave it on the filter setting for a while and you will find that the pressure will increase as the filter gets dirtier, when it get high (usually in the red ) you will have to backwash.
If you have a sand or DE filter the setting is filter in the case of cartridge filters it is filter as always unless there are other settings for your particular setup.
What type of filter do you have? If you have a DE filter then you may have cracks in the manifold that the tubes slot into or the filter tubes are falling out of the manifold. Either way you will most probably need to buy a new manifold.
As far as opening and closing nothing, just make sure your hose is filled with water it is eaiser to begin vacuuming, normally we attach the hose to the vacuum that goes in the pool then attach the hose to the skimmer then begin vacuuming if we do not loose our prime, if the pressure gauge on the filter is reading low you can probaly can start vacuuming if it is reading mid to high pressure it sometimes is best to backwash before vacuuming.
If dirt returns to the pool while you are vacuuming, it means there is a hole or broken item in the filter. If filter is a cartridge filter the could be a hole in the cartridge. DE filter, hole in filter fabric or broken plastic manifold. Sand filter - broken plastic fitting maybe.
Filter or circulation with pump running add chemicals.
It should be on "FILTER"
You can vacuum a salt water pool the same way you would a non salt water pool. If you are vacuuming on the filter setting, your filter will help to clean the debris out of the pool. If you are dealing with a very dirty pool and use the waste setting, you will be wasting some of the water from the pool in the process. Depending on how much water you take out and need to refill, you will most likely need to add some salt back in to get your salt level back to normal operating levels.
No leave it there otherwise all the leaves and rubbish will end up in the hair filter in front of the pump or worse still in the pumps impeller if you don't have a hair filter.
The "spider gasket" inside the valve has been destroyed by the chlorine and the water is blowing through the valve instead of going through the sand. Take the cover off of the valve by removing the screws on top and examine the gasket beneath. If this is not the problem, then I would replace the sand in the sand filter. Pool Masters
Try vacuuming now and then. Keep the windows closed when possible. Install and maintain an air filter. Keep dusty things out of the house.
The correct filter depends on the year and the model of your Honda which you did not list. Any auto parts store can sell you the correct filter if your Honda even has one.
Anyplace that sells filters can tell you the correct filter to install.
Use the main drain when backwashing, rinsing, or vacuuming. Use skimmer all other times to filter.