Low flow, poor suction; bubbles in pump & pool, mustard algae

[kahmeal]

First off thanks in advance for any help with this issue as I am completely new to pool maintenance and ownership. With that said, I am also far from helpless and certainly know my way around the internet and a toolbox. Hopefully I can provide enough information here that someone can point me in the right direction when it comes to getting this problem solved.

Background Info:
We recently moved into a home in Phoenix, AZ who's previous owners had no clue when it came to pool maintenance. The automatic water leveler was shut off, the filters were beyond dirty (starting pressure was near 40psi and the filter cartridges were nearly black) and the water was quickly approaching green. I cleaned the filters, lubed all the O-Rings (filter and pump housing), scrubbed & shocked the pool and brought the pH back to normal. The water is now clear and swimmable. I set the aqualink control panel to turn the pump on for 6 hours every night from 10pm to 4am. I keep 4-6 chlorine tablets in a floater at all times.

General Pool Information:
1. Pool is approximately 16,500 gallons and free form shaped.
2. Pool has a spa attached to it that is plumbed into the pool itself, both used to be heated. The heater (broken) was bypassed and new plumbing was installed that did not include the heater.
3. There is a water feature and aerator included in the piping. The water feature does not work as far as I can tell and is turned off via valves. The aerator does work but is off.

Pump Model: A.O. Smith Corp SQ1202 2.6hp
Filter Model: Pentair Clean & Clear Plus CCP520

(Potential) Problems:
1. The pressure on the filter reads ~10 psi upon starting and stays there or gradually gets to about ~15psi over time. From what I understand, this is too low.
2. The Kreepy Krauly automatic vacuum usually works but the suction seems poor and it doesn't move very fast. After it's been on for a little while it tends to get weaker. About 2 weeks after the filters have been cleaned the vacuum is nearly immobile until I clean them again. No noticeable change in filter pressure.
3. There are a LOT of bubbles coming out of the return jets whenever the pump is turned on after being off for a few hours. After it runs for a while there are still some bubbles coming out of the returns.
4. One return barely works at all (farthest from the pump) and when it does it's mostly bubbles.
5. The skimmers have fairly poor suction, they don't pull debris into the basket much and there's no visible swirling.
6. There is a small leak at the PVC joint where the water comes out of the pump housing and to the filter; This seems to be past the suction side so I am not sure if air is still getting in here.

When I took the pump apart to lube rings and make sure the impeller didn't have anything stuck in it, I noticed there were small cracks or what appear to be slits caused by chafing in the plastic housing that goes around the impeller. Here is a picture:


I made a quick video to give a decent visual overview of our setup that can be viewed on youtube here: http://youtu.be/L_R83KrAEeY

Again, thanks for your time and any help offered is much appreciated!

[PoolDoc]

1. The pressure on the filter reads ~10 psi upon starting and stays there or gradually gets to about ~15psi over time. From what I understand, this is too low.

Not necessarily. The issue is flow, not pressure.

The Kreepy Krauly automatic vacuum usually works but the suction seems poor and it doesn't move very fast. After it's been on for a little while it tends to get weaker. About 2 weeks after the filters have been cleaned the vacuum is nearly immobile until I clean them again. No noticeable change in filter pressure.

Dirty filters lower flow. Badly cleaned cartridges may need to be replaced. Low quality cartridges (most aftermarket cartridges) cause a variety of problems. This page will tell you how to clean, Cleaning-your-Cartridge-Filter-wiithout-Damaging-It!

Clean & Clear® Plus Cartridge Filters
Filbur FC-6475 Antimicrobial Replacement Filter Cartridge for Clean and Clear Plus 520 Spa Filter, 4-Pack
Unicel C-7498 Replacement Filter Cartridge for Pentiar Clean and Clear Plus (takes 4)

There are a LOT of bubbles coming out of the return jets whenever the pump is turned on after being off for a few hours. After it runs for a while there are still some bubbles coming out of the returns.

You have a suction leak. This can often reduce flow dramatically. And looking at the video, it's clear that you have a bad suction leak -- Vid cap:

One return barely works at all (farthest from the pump) and when it does it's mostly bubbles.

If you have normal flow, this means a piping problem - - often poor initial design and plumbing. If you have low flow, it may not mean anything.

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The skimmers have fairly poor suction, they don't pull debris into the basket much and there's no visible swirling.

This points to low flow. Try to find and fix the suction leak and see if that helps.

On your pool, the 4 places I'd check first are the pump lid, the pump inlet, and the (2) 3-way valves.








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There is a small leak at the PVC joint where the water comes out of the pump housing and to the filter; This seems to be past the suction side so I am not sure if air is still getting in here.

Suction leaks leak AIR INTO the piping; pressure leaks leak WATER OUT of the piping. Suction leaks reduce flow; pressure leaks, unless they are huge, do not. The leak on your pump effluent piping is trivial.

When I took the pump apart to lube rings and make sure the impeller didn't have anything stuck in it, I noticed there were small cracks or what appear to be slits caused by chafing in the plastic housing that goes around the impeller.

All normal.

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But . . . you need to take care of your mustard algae in the pool:




and the spa:



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And, you need to check on this crack:



before that part of the deck falls into the pool.

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By the way, you have an old Sta-Rite MaxEGlass or Duraglass pump. The AO Smith info is the motor, not the pump. Here are the manuals.
http://www.pentairpool.com/pdfs/maxeglasDS.pdf‎
http://pentairpool.com/pdfs/S691.CMax-E-Pro.pdf
http://www.pentairpool.com/pdfs/DuraGlasOM.pdf
http://www.pentairpool.com/pdfs/DuraGlasIIOM.pdf

[PoolDoc]

Basically, you need to take the following steps:

1. Find & fix the suction leak, and see if that solves the flow problem.

2. Read the Best Guess page, linked in my blue signature block above.

3. Order a K2006 test kit. (link above).

4. Purchase a local OTO phenol red test kit (yellow / red drops) and use it to test.

5. Make SURE your chlorine is in the OTO *dark yellow* ALL the time. Further adjustments will need to wait for the K2006.

6. Brush your mustard algae spots 2 -3 times per week. Add a gallon of 8.25% bleach each time BEFORE you brush; part in the spa, the rest in the pool.

7. Check your filter cartridges; clean them properly; order spares or replacements as needed.


Good luck!

[kahmeal]

EXACTLY the kind of response I was looking for, thank you so much Ben! I will take steps to implement all this in the coming week.

The deck cracks aren't too bad yet according to the original pool builder (the original owner of the home was forward thinking and kept all documentation with the house) and can wait until we do a major deck overhaul in the future, something we've already discussed as a definite undertaking.

The algae I've been scrubbing but the last few days we've been a bit too busy and it's gotten a little out of control.

Do you have any recommendations on methods to use for tracking down the suction leak? I've heard of using smoke near suspect areas to see if it gets pulled in?

[mas985]

The bottom valve in this picture on the suction side of the pump (without the actuator) is set to restrict the flow on the main line. This will increase the suction head and decrease both flow rate and filter pressure plus it can cause the pump basket to leak air and draw in bubbles. Set that valve such that the handle is pointed along the common pipe and see if that improves things. BTW, do you know what those two lines go to (e.g. skimmer and main drain)?

[PoolDoc]

Good catch. Thanks, Mark.

[PoolDoc]

Do you have any recommendations on methods to use for tracking down the suction leak? I've heard of using smoke near suspect areas to see if it gets pulled in?

I've never heard of using smoke, and I'm pretty doubtful. The airflow is almost certainly not great enough for that to work; a little air goes a long way in messing up water flow.

Looking and listening are the only two methods I've ever used. You need to LOOK for possible leaks, and then check them. People have used a variety of things to check for leaks. I've sometimes used silicone, since if the leak is small, I can not only find it -- as the silicone is sucked it -- but stop it at the same time. K-Y Jelly can also be used, and you don't have to worry about making a mess or causing damage, which might happen if you silicone-ed a leaking 3-way valve.

Sometimes, you can hear a small leak. But this usually means first locating likely locations, and then listening. Your pump is pretty loud, so that's probably not an option. (I work with large commercial pumps, and many of them have had 1800 RPM pumps I installed, and I forget how loud the 3600 RPM pumps used on home pools are.)

[kahmeal]

The bottom valve in this picture on the suction side of the pump (without the actuator) is set to restrict the flow on the main line. This will increase the suction head and decrease both flow rate and filter pressure plus it can cause the pump basket to leak air and draw in bubbles. Set that valve such that the handle is pointed along the common pipe and see if that improves things. BTW, do you know what those two lines go to (e.g. skimmer and main drain)?

Sorry it took me a while to reply, been a bit caught up with other things the last few days. I have not yet had a chance to track down the leak, however as far as that handle goes; The position it's in is as far as it will turn in that direction. The other possible positions are 12 o'clock which completely blocks all water to the pump and then 2 o'clock which partially blocks the right pipe the same way the left is now partially blocked. Unfortunately these two pipes are not labeled so I'm not sure where they go.

I made another quick video showing the piping a little better, if you can figure out exactly what each/valve does and what they should be set to that could help me a bit as I'm still not quite sure what they all do or what they should be set to.

http://youtu.be/x6C8bvSSeRE

Also, is the pool swimmable a few hours after adding the 1 gallon of 8.25% bleach and scrubbing the algae or should we not be using it until that problem is gone?

[kahmeal]

Well I've tried a few different things so far:

1. I ran water over all the different joints in the suction side piping while watching the return jets to see if the bubbles diminished at all -- they did not. The pump lid still continued to show a lot of air.
2. I used smoke around all the pump joints to see if any was getting pulled in -- none. Checked around the pump lid as well. Relubed the gasket just in case and closed the lid snug but not too tight.
3. I applied a high temp waterproof silicone around all the PVC joints on the suction side to rule out air leaks despite the lack of indication from the previous two strategies, just in case. After allowing it to cure all day, tried the pump in the evening and the problem remains.

At this juncture I am beginning to suspect an in-ground leak somewhere but have no idea what tracking that down entails or whether it's even feasible for someone like myself. I appreciate any and all feedback in this matter as it's beginning to look like it might get expensive and we really can't afford to throw too much money at this yet considering our recent move in and related expenses. Thanks so much!

[PoolDoc]

I've never really known if this stuff:

http://www.fixaleak.com/pools.html

works, or not. But given what your options are, it might be worth trying. Be *SURE* to read the instructions on the page above, before deciding to buy. Here are two links to Amazon for the product:

#1 Marlig Fix A Leak Pool Leak Sealer - 32 oz
#2 Marlig Fix A Leak Pool Leak Sealer - 32 oz

If you do use it, please let us know whether it works or not.