Possible Insufficient Pump and New Pump Possibilities

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Picked up a new cheap gauge from Leslie's, and it reads about 20.5-21ish psi. If I turn on the 3/4" feed to the slide, it drops to a solid 20 psi, if not a hair under.

I am definitely getting better flow since removing the chlorinator. I am going to look into a Liquidator, since it has pretty high marks and is inexpensive.

I have no idea what the piping looks like underground. I would think that if there was a breakage or collapse, I would not be seeing nearly the flow out of the returns that I am. I guess we can only assume a very poor design.

So, I guess one option would be to get a pool company to come out and check it out. I am not sure what they can do besides dig up what they can, which is VERY unappealing to me at the moment. I am sure it would be a venture in the thousands of dollars.

The other option would be to live with it. What honest consequences are there to running my setup at 20psi in the long term? If it means a blown motor every few years, I can live with that. If I decide to go with a VS motor, can my piping handle a slightly higher flow rate to simply clear an algae bloom? I would obviously run the pump at a much slower rate during most of the season, which i would think would mostly negate the high pressure.
 
There isn't much downside to leaving things as they are. High head loss is not hard on pumps. In fact, just the opposite. They draw less power and run cooler.

However, as you know, pumps produce less flow rate with more head loss so as long as you can live with that, you should be fine.
 
That is good news on that front. I will probably look at a VS motor for next season. The one I am looking at is the 1.65 HP that is used on the Pentair Supermax VS. It bolts right to the Super pump housing.

http://www.pentairpool.com/products/pumps-inground-supermax-vs-variable-speed-pump-463.htm

Looking at the performance curves, It looks like it has enough juice to power through some pretty high head and give me close to the 50gpm to get the 3x turnovers per day for beginning of season cleaning, and at the same time be able to be dialed back for slow flow during the rest of the season. Would this motor bring the pressure too high for my plumbing setup, or would it work ok?
 
I guess I should have been more specific. The actual motor I am looking at is an A.O. Smith ECM16CU, which shows it should be a direct replacement for the super pump wet end. It looks almost identical in specs and computer interface to the Supermax VS, and the pentair site was the only place I could find performance info. I may be going about this the wrong way, but it seems to make sense.
 
That pump has a very different set of performance curves. I guess I will have to do some more homework on pumps before I settle on something. I was hoping to get away with a motor switch only, but it sounds like I may just need to look at an entire pump.

I know my pressure is "high", but I would like a little more juice to start the pool up at the beginning of the season. What I have now doesn't turn the water over enough to efficiently clear an algae bloom, but it works fine keeping the pool clear. Is there a way you can estimate my total "head" and my target gpm based upon the pressure and the measurements I have given you?
 
Clearing algae has almost nothing to do with turnover or pumps.

Have you read in Pool School how to clear an algae bloom (aka SLAM)?

Using the correct techniques you could clear algae from a 100k pool with an Intex pump.
 
Yes. I opened and SLAM'ed the pool a week ago Thursday, and the pool is finally getting clear. I figured getting to 8 hours per turn over was the overall goal of the pump and filtration system. Pretty sure mine does not move that much water. However, if you think the pump and filter I have is sufficient, and clearing a 25k swamp in 10 days is reasonable, then I will probably keep everything as it is.
 
your pump and filter will work fine, we have people that have way smaller filters, it just takes longer.... the sand filter is the slowest filter but it is also the easiest filter to use :)
 

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When I was SLAMing the pool, I used the Tf100 kit to test every couple hours until the FH held steady. Poolmath told me that shock is 16, mustard shock is 24 @ CYA 40, so I held it at 20 until the pool cleared up. It took about a week for it to start to clear up, and it finally was clear today. I only held shock level for about 5 days and let it fall back down. I felt pretty confident that the algae was dead after 5 days, but it felt like forever for it to clear up. Tis the downside of the sand filter.
 
Yes I stopped the shock when my CC was .5. I also bought some DE a few days ago, and it helped a bit, but reduced the flow quite a bit. It took about 2 cups to get the gauge to go up the 1 psi recommended in the article on this site, so I have been using about 1 cup to keep the flow going a bit better.
 
1 psi shouldn't reduce flow much or are saying after that when the pressure rises more, flow reduces because that should happen as the filter collects more algae
 
Yes, when I added the full dose of DE and waited about an hour, the flow was definitely less. I see what you are saying and it makes total sense. Would a more powerful pump be reduced to the same flow on my setup the same way (collecting tons of algae)? Is this why you are saying a more powerful pump really won't help?
 
You need to remove the algae and that causes the filter pressure to rise and that causes lower flow rate. So until the algae clears, you need to backwash frequently and continue to use DE. Otherwise it will take a very long time to clear.

A more powerful pump doesn't help much because under higher pressure, the pump doesn't produce that much more flow rate to make a big difference.
 
I understand now. I was under the impression that a more powerful motor would would be able to proportionally move more water through the filter while clearing algae. But, if any motor would end up limited to the same flow through the filter, then I can see why changing my motor would be a waste. The motor switch I have is Z-wave, tied to a relay, and the switch interfaces with my Smartthings hub. I can program on and off times at will to automate most of the season. My main concern has been trying to get through the algae bloom as efficiently as possible. I figured if a stronger motor could shave time off of the start of each season, the motor would eventually pay for itself. Thanks everyone for your help on this. I appreciate it!
 
Hi all. Sorry to resurrect an old thread, but I found the problem and solved it. My pump motor was frozen stuck upon opening the pool this year, so I needed to get a new pump. I went with a pentair 1hp superflo 2-speed. My electrical company has a rebate for it, so I ended up paying about $100 for it. Score. Couple that with my adding of a Salt Water Generator, I decided to re-plumb the pad. I re-plumbed everything with 2-in, up from the original 1.5-in. Upon firing up the pump, the pressure at the filter was 27 psi, and there was virtually ZERO flow through the return eyeballs. Something is not right here, so I decided that something needed to be done. I did some homework and a pinched flex pipe seemed to be just about the only possibility. To make a long story short, I started digging up the yard. I got about 6 feet from the pad and found the return flex pipe totally pinched off. After cutting that section out and splicing new flex pipe in, the returns move water like a champ! Victory!
 

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