Questions about pump and filter

I have an 18ft above ground pool. 52" deep. Approx 8300 gallons. I have a 1.5hp waterway 2 speed pump and a 22" milineum sand filter with 150 lbs of pool sand.

My first question is this a good combination? I run the pump on low when filtering and high when backwashing and rinsing.

I notice that when I turn the pump off, and switch the valve to backwash or rinse, water starts flowing through my waste line before I turn the pump on. Is this normal?

My pressure immediately after backwashing is not quite 2 psi. Is this normal? It seems a little low to me. Also even after running the pump for 2 or 3 weeks, the pressure does not seem to rise. I would expect the pressure to be going up. (This pressure is when the pump is on the low setting)

I have only owned my pool for about 3 months, but if I can buying a larger filter will make a big difference, then I am not opposed to doing this. I have been fighting my pool for the past 2 months and dumping lots of money in it by buying chemicals that the pool supply place has recommended. (I wish I would have found this site sooner)

Thanks for your help

Tim

A psi of 2 is a bit low, but may not be for the lower speed on your pump. One of the equipment guys can answer that better than I can.

You say you've been fighting your pool for the past 2 months--is the problem algae? Or some other problem? If it's a water chemistry problem, we can probably save you a LOT of money over the pool store, if you'll post a set of drop-based test results for us to look at...

I have definitely been fighting algea for the past 2 months. Unfortunately I did not find this site sooner. (I have probably spent $100 on phosphate remover alone) :(
I have the recommended test kit on order, so I will post results as soon as it arrives. In the meantime, I was trying to figure out if I was sold a much bigger pump and much smaller filter than I really needed.

Thanks

Tim

In a word...yes. You probably are okay with the filter you have, but a 1.5 HP pump is way too big for your pool. However, with it running in low speed, it may not be bad--Pooldoc, Mark, or one of the other equipment gurus should be able to better advise you there. I just know that my pool is roughly 25K gallons, I have a 300 pound sand filter and a 1 HP pump and it's plenty big enough.

Janet

I am concerned about the low pressure on my sand filter. When running on low it is about 2.5 psi. When I turn my pump on high it is around 11 psi.
I am getting good flow back through my return jet. Is it possible that not enough sand was put in my filter when it was installed? It is a 22" filter, and the installers put 150 lbs of sand.

Is there anything I can mess up by taking the valve off the top and looking into the filter to see how much sand is there? If I do, how high should the sand be?

Thanks

Tim

On a 2-speed pump you read the pump pressure at the high setting. My clean pressure is 15 PSI. The gauge shows 5 PSI on the low setting always, no matter how clean or dirty my sand filter may be.

With the pump OFF it is normal to get some water flowing out the waste line when the multi-port valve is set to backwash.

I Googled "Waterway 22" sand filter", got many hits, and learned that this filter requires 150# of sand, so it sounds like your installers were right on.

Tim, I think that what is a normal pressure varies considerably between pools. In my set up, when I run the pump on low, which is 99% of the time, my pressure guage reads zero. On high, it reads about 8 psi, when the filter is clean. I really don't worry about the low psi reading because the water from the returns is quite powerful.

Tom

Good point, Tom, and it reminded me of something I had meant to include in my previous comments: the PSI number is also related to the sensitivity of the gauge.

In prior years I used 0 - 60 PSI gauges. The pump pressure on low was near 0 and 8 PSI on high. This year I bought a 0 - 30 PSI gauge and get 5 PSI on low and 15 PSI on high. What's important to me isn't so much the number as the consistency over time of the pressure reading at the different pump speed settings, just as I look for consistency in my water chemistry numbers. A variation is easily noted and acts as an alert that something might need my attention.