Should I change my plumbing?

[BobVila]

I have a Tristar 900 1.85HP pump for my pool which is somewhere between 25-30k gallons. I just moved into this house and it is the original pool from 1978. I have two 1.5 inch skimmers pulling from the pool and a single 1.5 inch pulling from the spa. The main drain at the bottom of the pool was removed (plugged) by the previous owners. My issue is that I don’t seem to get a good flow rate to keep the pool as clean as I would like. I’m trying to avoid an expensive overhaul, as ideally it would be nice to re-plumb with 2 inch skimmers and add another skimmer and/or drain to the main pool. However, is there something I can do to help? My pump never seems to be fully primed (but no leaks as far as I can tell). The suction lines go from 1.5 to 2 inch and then 90 degrees into the diverter valve. Could this be part of the problem? Should I re-do the plumbing and replace elbows with sweeps? Get rid of the double 45 going into the pump? Would swapping out with sweep elbows help on the pressure side? See pics and thanks for your help.

 

[PoolStored]

None of your plumbing suggestions will make any appreciable improvements.
You have a decent pump.
I think that your issue is likely that your filter is dirty, or you have algae.

1. Clean your filter
2. Lubricate all the o-rings (lid and drains) on your pump with silicone lube (magic lube II)
3. Do an Overnight Chlorine Loss Test (OCLT) to confirm that you do not have algae. Link-->Overnight Chlorine Loss Test
4. Fail the OCLT, time to SLAM. Link-->SLAM Process

 

[Newdude]

My pump never seems to be fully primed (but no leaks as far as I can tell).

Its pretty common with variable speed pumps. As long as it doesn't go below the lid, it's fine.

Many run full speed for a few mins a day to clear the bubble.

 

[Jimrahbe]

Bob,

Why are you sucking water from the Pool and the Spa at the same time???

Generally, when you have a single pump, you are either in the Pool mode, or the spa mode, not both at the same time..

You suck water from your skimmer(s) and then return most of the water to the pool, but send a little water to the spa causing it to spillover into the pool.

It appears that you are sending way too much water back to the spa, because you are sucking water from the spa.. It does not make sense..

When you suck water from the spa, that just reduces that amount of suction going to the skimmers..

Since you only have two suction inputs to your pump, I must assume that both of your skimmers use the same pipe.. This is not a good design..

Show us some pics of your skimmers.. looking down without the basket.. Also looking between the mouth of the skimmers and the basket area.. For a skimmer to work well, there must be a weir door, which is often missing on older pools.

Your plumbing is not the issue, something else is going on.

While low water, or air in the top of the pump basket, is pretty common when running at a low rpms, your pump does not look right to me. How fast is it running in your pics??

Thanks,

Jim R.

 

[BobVila]

Bob,

Why are you sucking water from the Pool and the Spa at the same time???

Generally, when you have a single pump, you are either in the Pool mode, or the spa mode, not both at the same time..

You suck water from your skimmer(s) and then return most of the water to the pool, but send a little water to the spa causing it to spillover into the pool.

It appears that you are sending way too much water back to the spa, because you are sucking water from the spa.. It does not make sense..

When you suck water from the spa, that just reduces that amount of suction going to the skimmers..

Since you only have two suction inputs to your pump, I must assume that both of your skimmers use the same pipe.. This is not a good design..

Show us some pics of your skimmers.. looking down without the basket.. Also looking between the mouth of the skimmers and the basket area.. For a skimmer to work well, there must be a weir door, which is often missing on older pools.

Your plumbing is not the issue, something else is going on.

While low water, or air in the top of the pump basket, is pretty common when running at a low rpms, your pump does not look right to me. How fast is it running in your pics??

Thanks,

Jim R.

Thanks for your thoughtful response. I changed the diverter valve so that all of the suction is coming from the 2 skimmers. Yes, poor design. It is about 20 feet to the closest skimmer. When I get the time, would you recommend trying to plumb the skimmers separately and install a 4 way jandy valve?

I’ve attached a pic of my pool and the skimmer. Both skimmers have the weir door functioning normally. Pump runs at 2875 rpm for about 8 hours then throttles down to 2000 rpm rest of the time. I suppose angling down the eyeball outlets would be preferred since there is no main drain? The deep end is 9 feet. Thanks again.

 

[BobVila]

None of your plumbing suggestions will make any appreciable improvements.
You have a decent pump.
I think that your issue is likely that your filter is dirty, or you have algae.

1. Clean your filter
2. Lubricate all the o-rings (lid and drains) on your pump with silicone lube (magic lube II)
3. Do an Overnight Chlorine Loss Test (OCLT) to confirm that you do not have algae. Link-->Overnight Chlorine Loss Test
4. Fail the OCLT, time to SLAM. Link-->SLAM Process

Okay thank you. I did a tear down of the filter yesterday, so we can rule that out. Pump is all lubed up as well. I will do the algae test tonight. Thanks for your suggestions.

 

[Jimrahbe]

Bob,

I would not re-plumb the skimmers just to do that, but if you were doing a lot of other things, then it might make sense at the time.. A pretty big and expensive job by itself..

When you say you "don't get a good flow rate to keep the pool clean".. what is it that you mean?

In general, things that fall into your pool should get captured by your skimmers.. Things that fall to the floor of the pool need to picked up by a cleaner of some type.. None of that stuff will be effected by the flow rate.

So, is the whole problem that you don't think the skimmers are doing their job, or???

I'm just trying to understand the problem, so that maybe we can suggest a possible solution.

Edit.. I don't think that angling down your pool returns will make any difference at all.. I like to see the returns set so that they push the water in the pool in a circle... Kind of like a large flushing toilet bowl. I find this drags more floating stuff in front of the skimmers..

Thanks,

Jim R.

 

[Jimrahbe]

Bob,

You have a small VS pump.. So you have to run it faster to move more water..

But... I just noticed that you have a heater by-pass set up..

I suspect that if you opened the by-pass, so that your return water would bypass the heater, that should greatly improve your water flow..

Check your filter pressure at 2875 and then bypass the heater and check the filter pressure again.. Tell us what you get..

Have you tried that before???

Thanks,

Jim R.

 

[BobVila]

Bob,

I would not re-plumb the skimmers just to do that, but if you were doing a lot of other things, then it might make sense at the time.. A pretty big and expensive job by itself..

When you say you "don't get a good flow rate to keep the pool clean".. what is it that you mean?

In general, things that fall into your pool should get captured by your skimmers.. Things that fall to the floor of the pool need to picked up by a cleaner of some type.. None of that stuff will be effected by the flow rate.

So, is the whole problem that you don't think the skimmers are doing their job, or???

I'm just trying to understand the problem, so that maybe we can suggest a possible solution.

Edit.. I don't think that angling down your pool returns will make any difference at all.. I like to see the returns set so that they push the water in the pool in a circle... Kind of like a large flushing toilet bowl. I find this drags more floating stuff in front of the skimmers..

Thanks,

Jim R.

Good question. My water is clear because I am good with keeping up with the chems. I guess my concern with the flow rate is based on comparing this pool with my last. If I watch some leaves or pollen sitting on the top of the pool within a few feet of the skimmers I’m not seeing the pull that I had at my last pool, particularly if the pump is down at 2000rpm. I’ll point the eyelets to one direction to see if the toilet bowl affect helps. Additionally there is a tremendous amount of soot at the bottom of the pool. I have a Polaris that runs about 6-7 hours a day and I brush a couple times a week. This helps, but not enough.

 

[BobVila]

Bob,

You have a small VS pump.. So you have to run it faster to move more water..

But... I just noticed that you have a heater by-pass set up..

I suspect that if you opened the by-pass, so that your return water would bypass the heater, that should greatly improve your water flow..

Check your filter pressure at 2875 and then bypass the heater and check the filter pressure again.. Tell us what you get..

Have you tried that before???

Thanks,

Jim R.

Good point. I had forgotten about the heater. If I bypass the heater and completely close off the spa (both suction and return), filter is 9psi. If I open the return line to the spa the psi drops to 7 (partially open) or 5 (fully open). Pressure actually goes a tad bit up to 9.5 if I run the lines through the heater. That’s strange…

 

[Jimrahbe]

Bob,

Filter pressure is not what many think...

High pressure is bad and low pressure is good..

Filter pressure is really a measure of how hard it is to send the water back to the pool.. When you insert the heater, you are adding a restriction to the water flow and this increase the filter pressure..

When you are in the pool mode, most of the water should go to the pool, but a little water must always go to the spa.. This causes the spa to spillover into the pool and this is what keeps the spa water fresh..

I thought by-passing the heater would effect the flow a little more, but I would suggest that you leave the heater bypassed unless you plan to use it.
I suspect that your old pool had a single speed pump or a much large VS pump..

You really can't compare how the skimmers look when using a single speed pump vs. and variable speed pump.. When using a VS pump, it 'almost' looks like the skimmers are not working but they are.. Skimmers never 'reach out into the pool and pull stuff in'... When using a VS pump you just have to have a little patience.. My pump runs at 1200 rpm (no heater) and at first glance it appears my skimmers do not work. But.. I use hairnets in my skimmers and I can tell you they work just fine.. I think they are shy, as they just don't work if you are looking at them..

If later in life, your pump fails, I would recommend a 3 HP pump as they can move a lot of water at a lower rpm.

I use a robot cleaner.. Not sure that would solve your problem, but I do know it would be a lot less expensive than redoing all your plumbing...

Check out your air bubble under the pump lid with the heater bypassed and see if it makes any difference..

Is it an actual bubble or more like foam?? You may have a small suction side leak.. Show us a couple more pics of your pump lid in operation..

Thanks,

Jim R.

 

[BobVila]

Bob,

Filter pressure is not what many think...

High pressure is bad and low pressure is good..

Filter pressure is really a measure of how hard it is to send the water back to the pool.. When you insert the heater, you are adding a restriction to the water flow and this increase the filter pressure..

When you are in the pool mode, most of the water should go to the pool, but a little water must always go to the spa.. This causes the spa to spillover into the pool and this is what keeps the spa water fresh..

I thought by-passing the heater would effect the flow a little more, but I would suggest that you leave the heater bypassed unless you plan to use it.
I suspect that your old pool had a single speed pump or a much large VS pump..

You really can't compare how the skimmers look when using a single speed pump vs. and variable speed pump.. When using a VS pump, it 'almost' looks like the skimmers are not working but they are.. Skimmers never 'reach out into the pool and pull stuff in'... When using a VS pump you just have to have a little patience.. My pump runs at 1200 rpm (no heater) and at first glance it appears my skimmers do not work. But.. I use hairnets in my skimmers and I can tell you they work just fine.. I think they are shy, as they just don't work if you are looking at them..

If later in life, your pump fails, I would recommend a 3 HP pump as they can move a lot of water at a lower rpm.

I use a robot cleaner.. Not sure that would solve your problem, but I do know it would be a lot less expensive than redoing all your plumbing...

Check out your air bubble under the pump lid with the heater bypassed and see if it makes any difference..

Is it an actual bubble or more like foam?? You may have a small suction side leak.. Show us a couple more pics of your pump lid in operation..

Thanks,

Jim R.

These pics are at 1800rpm. Doesn’t really change anything at higher rpm. It doesn’t look like bubbles or foam but that the basket just isn’t filling all the way. I’ve heard these pumps tend to do that. No bubbles coming out of the eyelets except right when I turn the pump on. My previous pump was an intelliflo 3 hp so I’m used to the pump basket being full and no bubbles.