Your filter may be clean and normal at 9-10 psi, but your neighbor's filter gauge could run higher, and be clean at 15-16 psi. Some systems with very low resistance can run very low pressures, barely registering, while other filter systems can run quite high, pushing 30 psi when the filter becomes dirty.
If anything could be considered “normal”, it would be about 10 psi. Most filter systems are designed to operate in the 5-15 or 10-20 psi range. The way to find out your particular correct pool filter pressure is to clean or backwash the filter thoroughly and empty the pump and skimmer baskets.
The most common reason for high pressure on your filter pump is a dirty filter. Whether you have a sand filter, DE filter or cartridge filter, dust and solid particles will slowly clog your filter causing the pressure to rise. To fix this, backwash your filter or in the case of cartridge filters, hose it out.
In most high-rate sand filters, it's time to backwash when the pressure differential reaches 18 to 20 psi. But if the system has only an inlet pressure gauge, you should backwash when the pressure increases by 8- to 10 psi from initial post-backwash readings.
High swimming pool filter pressure is usually the result of a lot of particles being filtered out of the swimming pool water. When pressure rises it is time to backwash the filter if you have that option with a sand or diatomacesous earth (DE) filter.
The pressure gauge should read approximately 50 - 70 kpa when the filter is clean. Backwashing is indicated when the pressure exceeds 70 kpa.
The most common reasons why a cartridge, sand, or DE filter's pressure rises quickly, even after cleaning or backwashing, is a clogged or blocked filter, algae or old filter elements. If any of these things are wrong, the pressure can rise rapidly in minutes, hours or days.
Also, seems like you are waiting way too long to clean the filter. We generally recommend cleaning when the pressure goes up 20-25%. So that would would be around 19psi not 30.
Adding too much DE to your pool may cause multiple negative results. These ramifications include a clogged skimmer, turning the pool cloudy, reducing the circulatory pressure in the pool and putting too much work on your pump that may result in eventually breaking the pump.
If you do not add enough DE to your filter, then the grids are not totally coated with DE and the dirt that goes into your filter will attach itself right to the fabric on the grids and will not backwash off. This will cause your filter to short cycle (go very short times between backwashing).
What is a Pressure-Side Pool Cleaner? A pressure-side pool cleaner connects either directly to a dedicated pressure cleaner line or a return outlet in your pool. The dedicated pressure line or return outlet is the last part of your pool's filtration system.
The first thing to do to increase the suction is to check for blockage and air leaks. If one of the skimmers does not suck, it would be necessary to remove the basket from the skimmer. Then check if there isn't a flow control valve at the bottom of the skimmer, which would be almost closed.
Add diatomaceous earth (DE) to your pool skimmer, stick to around a scoop or two – no more than the size of a 1lb coffee cup. The moment you do this, go to the pool jets to see if it is returning DE into the pool, or if the water suddenly looks cloudy. If it is, you likely have an issue with your filter.
The most common reason for weak jets is an air leak. An air leak would come from the suction side of the system. This would be the area between the skimmer and the pump. One way to determine if you have an air leak is by looking for air bubbles coming out of the return jets.
It could be a clogged pump basket, impeller, pipe, or skimmer basket. It could also be a closed or broken valve before the pump. In some cases, the pump may have an air leak and is drawing in more air than water. This can reduce filter pressure (and filtration ability).
The rule of thumb is generally 8 hours, although it could be anywhere from 6-12 hours, depending on your pool's size. Each pool is unique, so to keep your pool pump efficient and effective, you need to figure out exactly what your pool's turnover rate is.
Most pool filter systems should have a pressure of 50-75Kpa (kilopascal) or 10 – 25 psi.
The inlet, or suction side of a pump is the point of lowest pressure in a given pump. For positive displacement pumps, the lowest pressure occurs just prior to rotor meshing; for centrifugal pumps, lowest pressure is near the eye of the impeller.
Add enough water until the pressure rises significantly, 15 psi or so, then shut off the water on the small valve on the pressure stick, and watch the pressure gauge. IF pressure holds (give it 60 seconds), the line is good, and you can move on to testing others lines or pipe runs.
A DE Scoop is specially designed to measure DE powder and 1 scoop is equal to 1/2 lb. of DE powder. To determine how many scoops or coffee cans of DE your filter requires take your filter square footage and divide by 5 (this would be after a full cleaning).
Do not operate your filter pump without having the D.E. powder coating the grids, or you will see the filter pressure rise very quickly, and if left in this manner the grids can collapse or the fabric can become clogged or damaged. As the pressure gauge on a D.E. filter increases, flow rate decreases.
After backwashing, new DE must be added to the filter. Add the entire amount of DE the filter recommends. If you see DE returning to the pool, vacuum it to waste, after it settles. The next time you backwash and recoat, decrease the amount by 1 pound.
You should clean your DE filter at least once every month or whenever you're pounds per square inch is 8 to 10 pounds above the normal starting pressure. Cleaning your DE Filter involves three basic steps: Backwashing, Cleaning the manifold and grid and adding new DE.
Waterway Crystal Water – 60 sq. ft. = 4.8 pounds of DE.