Hello all. I have lurked around the site/forum for a couple of seasons now and have run into a problem that needs to be addressed.
I purchased my house with the pool early last year, so I have had a full season and the start of this season to try and learn what I needed to to make the pool work as best as possible. The amount of knowledge on this site/forum is staggering, and I have learned much.
1. 25,000 gallons, oval shaped, 3 ft. shallow end - 8 ft. deep end. The pool was installed in the mid 80's.
2. 1 skimmer and 1 main drain
3. 3/4hp Super pump
4. S244T sand filter, I replaced the sand last spring, filter pressure 22 psi (verified with 2 different gauges)
5. CL200 chlorinator
6. Main drain is 40 ft/ from the pad, skimmer is 42 ft, (straight measurements). The pad is at water height.
7. All of the piping is 1.5". The main drain and skimmer run the full length as separate pipes and "T" right at the pump. There is 1x 1.5" pipe for the returns, which runs to 4x eyeballs on each side of the pool.
8. I have no idea how the plumbing underground is routed.
There is not much flow to the return eyeballs, even after a backwash. I blew out the suction and return lines to be sure there was nothing blocking the pipes. I also check that the impeller wasn't blocked. It doesn't take much more than an hour for the flow to cause at least 1, sometimes 2 of the eyeballs to stop flowing. The pool is cloudy but not bad. The pressure remains steady. I can't see how the filter would be getting clogged that quickly. Trying to filter the dead algae was a nightmare.
After doing extensive reading on pipe head and pumps, I have come to the conclusion that my 3/4 hp super pump is inadequate for the amount of head the pool has. With most of the underground plumbing unknown, I only know the pressure side head: 2.31 x 22 psi = 50.82 ft of head. I would imagine with 2x full 1.5" suction pipes from the drain and skimmer that the suction head really wont add much more. Is there a way to guesstimate the suction head without a vacuum gauge?
That being said and looking at the head curve for my pump, it looks at though there is about 25gpm flow at best, certainly not enough to get a turnover every 8 hours. This would require about 50 gpm.
Getting to my question: I am looking at options for a more powerful/higher head pump. Each option get most expensive. I am trying to keep upfront costs down, but I am also mindful of the long term costs of electricity of single speed vs. 2 speed vs. variable speed.
1. I can replace the motor on the Super pump with a Super II motor to handle the higher head.
2. I can replace the motor with a viable speed to handle the higher head for cleaning and such, with the ability to dial it down for general clean filtering and saving of power.
3. I could replace the entire pump with something like an Intelliflo, which gets good ratings on this forum. However, is this option total overkill for my plumbing setup?
Thanks in advance for any help you may offer.