Poor circulation and pump pressure issues...

[Ripper70]

Hey All,

My pool equipment is not performing well and has been gradually getting worse as this season has worn on. I'm hoping I can get some advice to cure my ills before I close it up for the winter. At this point my return jets are putting out a very low volume of water and my circulation is suffering to the point where I'm getting algae blooms that require constant attention.

Here's what I can tell you about my situation:

At the start of the season most everything seemed to be functioning fine. I did the deep cleaning of the sand filter and hooked up the pump and in about a week had a crystal clear pool. I have three Venturi return jets and two opposing skimmers which I orient with two pointed upwards and one pointed down. I began to notice that the upward pointed jets were not agitating the surface of the water as aggressively after running the pump for a few hours. My remedy for this was to backwash and rinse every few days and this action seemed to work to get the water flowing again.

However, gradually it required the backwash/rinse action more frequently to the point where I was doing it several times a day. Still, it worked to solve the circulation issue. Now, unfortunately, this is no longer the silver bullet cure. I get very poor circulation and not enough suction to vacuum which is making it difficult to keep the algae in check.

In an effort to fix the problem I purchased one of those rubber plumbing bladders that attach to a garden hose and tried blasting out the return lines in the hope that perhaps there was a pine needle dam obstructing the flow at one of the PVC elbows in the line. No go. Didn't change anything.

So, I'm now left to wonder what other steps I can take to troubleshoot this problem.

I did a few tests today which yielded interesting results, but I'm not sure what they mean. Let me explain.

I have a waste line that empties out onto the street where I can see how the water flows when backwashing/rinsing my filter. When backwashing the water shoots out like a firehose but when rinsing it dribbles out by comparison. I actually resorted to vacuuming to waste today because it was the only way to get the pool clean. I don't know if this is an indication of anything in particular, but I thought it was worth mentioning.

Anyway, if any of you experts have any recommendations for me, I'm all ears. I'll be closing up the pool in a week or two but was hoping to have some idea of how to start next season of successfully.

Thanks in advance for any advice.

Ripper

 

[mknauss]

Do you have some test results?

Sounds like an algae issue. What does your water look like?

Take care.

 

[Ripper70]

Well, I do indeed have an algae issue. But I believe that the circulation issue is at the root of it. The algae issue I can deal with. The pump issue is another thing altogether. FWIW, the pump was one I purchased the season before last when my old one failed. So, I'm pretty sure I can still reasonably expect a few more seasons out of it.

I'm confused though, why I would get adequate suction form the pump when the multivalve is on waste but nearly nothing when on the filter or rinse settings.

 

[mknauss]

Because the filter is plugged with algae. On waste the water does not go through the filter. On filter and rinse it does.

Algae is a chemistry problem, not a filtering problem.

 

[Ripper70]

But all this started while and despite the water being clear and my test results spot on.

To answer your earlier question my test results are:

FC - 12.5
CC - 0.5
Ph - 7.1
CYA - 50
TA - 50

I have been regularly shocking the pool in an effort to combat the algae blooms so that's the reason for my currently high FC readings. Usually I get readings in the 7.5 range. I brought the FC up to shock levels after these results from earlier today so I expect that they're closer to 22 or so.

 

[mknauss]

Follow the SLAM Process process. To completion. Read the article.

 

[Ripper70]

Is it possible that there's some kind of mechanical problem that's causing my pump pressure issues? After all, this circulation problem had been brewing since before the algae showed up. I believe the algae is blooming because I'm not getting adequate circulation. Not the other way around. All the slamming and brushing I can throw at it won't resolve my algae woes or cure my circulation problems if all I have is a weak dribble of water coming out of the return jets and skimmers that barely suck water, will it?

 

[mknauss]

If your multi valve is not leaking I am not sure what else there is but a plugging filter. You could deep clean your sand filter. See Pool School.

 

[Ripper70]

I've done the deep clean at the start of the past three seasons. Maybe I need to replace the sand? The pool was built about 25 years ago (long before I owned the home) and I'm guessing the equipment may be past it's useful life. I've been applying quick fixes and bandaids every year. New pump, re-plumbing above ground pipes, eliminating a puck chlorine auto feeder, new mechanical timer, new vinyl liner, etc., etc. ad infinitum. Never replaced the sand, though.

As for chemically balancing the water, with the help of you and your colleagues here on TFP, I've become a pretty darn good maintenance guy. I owe everything I know about pools to you guys & gals. That's why I'm expecting that this is something more than just needing to SLAM. Funny you mention the multiport valve, because I thought at first that maybe the problem lies somewhere in that mysterious contraption. Perhaps a faulty port or some such thing?

 

[mknauss]

Sand does not go bad. Now it can be solidified by pool store potions (floc, clarifier) or it can scale up, but it should last forever.

My only thought on the multi valve is that not all of the flow is going through the filter when on filter. But it would have to be going to waste (you would be losing water) or creating an internal back pressure.

I have no experience working on the valves. Other members will need to help with that.

 

[Ripper70]

Pool clarifier, huh? Well, I'll be. We here in the northeast have had allot of rain this season. Back in July our area got swamped at a time when I was out of town for a long four day weekend. Came home to a pool full of tree debris, clogged skimmer baskets and a relatively minor algae bloom. Now, I have no main drain. I cut the line off at the filter a couple of years ago because it was leaking and causing my pump to suck air. Too expensive to fix/replace and have been able to get by without it. In an effort to hasten the removal of the algae, I used (for the first time) a clarifier. Cleared up the pool after a couple of weeks with maybe four or five applications. Of course, I never made the possible connection to my circulation issues.

Could this be the cause of my problems, do you think? If so, would a deep clean of the sand filter be the correct course of action?

 

[Costas > DownUnder]

Could this be the cause of my problems, do you think? If so, would a deep clean of the sand filter be the correct course of action?

In the rare instance where we would use a floc or clarifier - we would always suggest that people vacuum to waste and not through the filter material.

If you were vacuuming through the filter and not to waste then the majority (all?) of that sludge would now be trapped in the filter media.

Deep clean will be required and if it is really bad ie stuck to the sand and causing it to clump severely then your only option may be to remove the sand and clean it outside the filter or even replace.

 

[Ripper70]

A followup:

Firstly, thank you, once again for helping to lead me to the solutions to my many pool related conundrums that I can't find without the assistance of the experienced folks here on TFP.

Today I took action based on the suggestion that the source of my circulation problems were the result of using a coagulating agent to help alleviate an algae bloom that occurred earlier this summer. So I removed the multi-port valve from my Hayward sand filter expecting to find exactly what I discovered. A three inch thick layer of coagulated crust had formed on top of the entire layer of sand in the filter. I reached into the filter tank and began pulling out slabs of debris that had been glued together from the coagulant, clearing out as much as I could grab with my hands.

Next, I slid my hand down the inside edge of the tank and realized that the crust had virtually encapsulated the entire inside wall of the tank, basically creating a shell around sand all the way to the bottom of the tank. So, I inserted a garden hose into the tank opening and reached my arm into the tank up to my shoulder and began breaking up the crusty encasement, flushing out as much of the debris as I could. I used a small strainer to scoop out the debris (mostly broken pine needles) and continued along this course for over an hour.

When I was finally satisfied that I had gotten all the gunk out of the tank that I could, I reassembled the filter, backwashed and rinsed three times and then kicked on the pump, with the multi-port valve set to filter, and lo and behold, my circulation was back to normal. Eureka!

Thank you again for your help. I'm sure it would be more effective to completely empty the sand from the tank for a more thorough cleaning, but since I'll be closing the pool very soon, I'll save that task for next season's opening.

 

[duraleigh]

Glad you found your issue. Do you have a working pressure gauge? That would have indicated your problem a long time ago.

Get one for next year if you don't have one.

 

[Ripper70]

I do have a working pressure gauge and it indicated that the pressure was running higher than normal. The evidence was apparent in the weak flow from the returns. I usually keep them pointed upward so I can get a visual on the general health of the system. That, along with a few algae blooms, indicated that there was a problem. It was figuring out the source, after trying to troubleshoot a possible obstruction in a return line, that had me stumped.

I'm wondering if there might be some value in changing my filtration system to another type. Part of my regular pool problem is that, although I have no trees on my property, I have a neighbor with a huge pine tree with a number of branches that overhang my yard. The tree sheds pine needles all year long. And I mean allot! I'm always conflicted leaving home for more than a few days because I know that, if I do, my skimmers will be clogged with pine needles by the end of day one and I'll return home to a pool with little to no circulation and an algae bloom in the works. Gets frustrating.

Over time the pine needles break into smaller pieces and make their way through the system into my filter tank. Backwashing helps somewhat, but much of the debris remains in my system. The picture below shows the kind of debris I pulled from the filter tank yesterday.

Do you think that there's a more effective filtration system that would better handle the pine needle issue? Maybe a cartridge filter system would be better? I'm open to suggestions.