Around 10 PSI if you have a 2 horsepower pump. It will vary, depending on the restrictions in the exit line. Pool Masters
No, backwashing is used during the cleaning of the sand, when the pressure has gone up on the filter, or you feel the vacuum is not doing its job that is when you should backwash.
Yes, after backwashing a pool filter you should add diatomaceous earth (DE) back to the filter immediately if you have a DE filter. If you have a sand or cartridge filter, there is no need to add anything after backwashing.
Your gauge could very well be bad, many pools that we took care of the gauge on the filter was bad, after backwashing the filter just check any of you lines going back to the pool and your should notice the pressure is a lot higher. A lot of people just check the flow by placing there hand at an outlet to check pressure than by walking over too the filter and reading the pressure, instead of buying a new pressure gauge.
A Hayward filter typically uses around 300-500 lbs of sand. The sand should be replaced every 5-7 years or when the flow rate decreases even after backwashing. Backwashing should be done when the filter pressure increases by 7-10 psi above the clean pressure.
It is not always necessary to backwash after vacuuming a pool, but it is recommended in certain situations. If you've vacuumed up a significant amount of debris or dirt that has clogged the filter, backwashing can help restore proper water flow and filter efficiency. However, if the vacuuming was light and did not introduce much debris, you might not need to backwash immediately. Always check the pressure gauge on your filter; if it indicates a rise in pressure, backwashing is likely needed.
There is a gauge on the filter that will indicate this. when as the pressure gets higher it indicates that there is a build up of dirt and the filter needs cleaning or backwashing. another indicator is if you note a marked reduction in suction at the static skimmer of the pool.
If you are backwashing more than you care to,or your filter pressue is high, or you put your hand against the outlet where the clean water is returning back to the pool and your hand does not get pushed away any of these reasons would be a reason to change the sand, depending on the size of the filter some filters need to be changed once a season every other season or not for years, bottom line you should only be backwashing after vacumning the pool. if your water in your pool is clean or clear I would say the sand is ok.
Depending on the size of the pool and the size of the filter and the amount of times you have to backwash, also if you have had a lot of rain then you may need to backwash more than usual. If you put the pool in and the filter and you know how old the sand is, if you are backwashing more than usual,change the sand. Also before you backwash check the pressure of the water going back into the pool, then backwash check the pressure again the pressure should for any size hayward pump push your hand away if it does not then change your sand.
Each time I backwash my pump head, the water comes out with extreme force. It has only trickled when something was going wrong. The pump may have been drawing air or the heads were dirty. During backwashing and rinsing, the water should be coming out with force. The pump pressure should even be lower when you return to filtering. Each time I backwash my pump head, the water comes out with extreme force. It has only trickled when something was going wrong. The pump may have been drawing air or the heads were dirty. During backwashing and rinsing, the water should be coming out with force. The pump pressure should even be lower when you return to filtering.
The oil pressure switch is located on the oil filter adapter. Find the oil filter and you should see the oil pressure switch.
The amount of diatomaceous earth (D) and other additives (E) you should add after backwashing depends on the size of your pool and the manufacturer's recommendations. Typically, for a DE filter, you should add around 1 pound of DE for every 10 square feet of filter area. Always refer to your filter's manual for specific guidelines, as different systems may have varying requirements.
As the filter gets clogged it restricts the flow of water and the pressure in the return line drops. The pressure gauge on the filter itself indicates the entry pressure and that will go higher as the filter becomes clogged. Don't ever allow the pressure to reach 40 PSI. Back-washing the filter should restore the pressures. Pool Masters