Freshly installed Liquidator, and some problems

[landrick]

Greetings, all. First-time poster, so please forgive my newbie-ness!

I'll try to condense this story as best I can:

I just joined my condo association's Board of Directors, and assumed responsibility for our outdoor pool. (I started with basically zero knowledge, but through some voracious reading--much of it here--have tried to get up to speed.)

We hired a new pool service, who, in theory, should completely take care of our pool. They recommended a Liquidator, and we had them install one last week. Then the adventure began...

When the installer left, I found the unit wasn't functioning; it wasn't filling with water. I removed the "IN" line check valve, and that cured the problem. (As a result, the tank drains to the level of the input float when the pump shuts off at night.) The unit could initially deliver and maintain a "5" on the flow meter; I set it around 2. The installer had no liquid chlorine, so I bought and added 2 gallons myself.

But after a few days, I saw the flow decreasing to the point where even with the valve wide-open, flow was only about 1.5. The problem seems to be supply pressure; the LQ tank is no longer completely filling up. My guess is that this relates to our filter condition: the LQ was installed just after our Hayward DE filter had been cleaned and was at top efficiency. Now, as the Hayward pressure indicator is nearly in the red, there seems to be insufficient pressure in the pool return line to fill the LQ. (And now, as of this morning, there is no refill at all and zero flow from the LQ.)

So, QUESTION 1: The installer tapped the LQ input fitting into our pool return line after the filter and about 3 feet past the heater. Would tapping the line closer to the filter make any difference in pressure? We would have several options, including about two feet back from the existing tap, a foot-long PVC section between the filter and the heater, or even the heater drain plug (if that's viable.) Could this help?

Then, today's more startling news: When the pool cleaning kid (who I believe is basically just taught "paint by numbers" with no real theory) shows up, he wants to add POWDERED (granulated?) chlorine to the Liquidator. ?!?!?! He says the owner "doesn't give him liquid chlorine." Pardon my ignorance, but what's the point of having a LIQUIDator if you don't use liquid chlorine?

So, QUESTION 2: Before I open a discussion with our pool vendor...is there any earthly reason you would want to run a Liquidator like that? Color me perplexed...

Thanks for any replies, and please let me know if I can provide more info.

 

[frustratedpoolmom]

Do not let him add powdered chlorine to the liquidator. He doesn't know what he's talking about.

As for the flow problems, someone with practical knowledge/hands on experience should be along shortly.

If the pool is not getting chlorine, make sure someone adds liquid in front of the return daily until the LQ is worked out....

Welcome

 

[JohnT]

Welcome to TFP.

If the flow from the filter has reduced that much, it's time to clean the filter again. That may be a weekly or even daily task, depending on the pool size, filter size and what kind of debris load your pool has. There is no magic number that indicates cleaning is needed. Clean it when performance drops. I also doubt that you'll get by for a week without adding liquid chlorine to your Liquidator if you have a higher bather load than a residential pool.

 

[Bama Rambler]

But after a few days, I saw the flow decreasing to the point where even with the valve wide-open, flow was only about 1.5. The problem seems to be supply pressure; the LQ tank is no longer completely filling up. My guess is that this relates to our filter condition: the LQ was installed just after our Hayward DE filter had been cleaned and was at top efficiency. Now, as the Hayward pressure indicator is nearly in the red, there seems to be insufficient pressure in the pool return line to fill the LQ. (And now, as of this morning, there is no refill at all and zero flow from the LQ.)

If I'm reading your post correctly, the reason the LQ isn't providing flow is because it isn't filling and therefore the outlet float valve is closed. If the inlet flow were enough would it work?

So, QUESTION 1: The installer tapped the LQ input fitting into our pool return line after the filter and about 3 feet past the heater. Would tapping the line closer to the filter make any difference in pressure? We would have several options, including about two feet back from the existing tap, a foot-long PVC section between the filter and the heater, or even the heater drain plug (if that's viable.) Could this help?

I'm assuming that you have a bunch of returns and when your filter is dirty you have almost zero pressure on your return line after the filter. In that case, tapping the LQ in the same line after the heater won't help. You need to tap the LQ inlet line into somewhere that it will see enough pressure to flow water into the LQ inlet float valve. Between the filter and the heater might do it if the heater is providing any resistance to flow when the filter is dirty. The only way to know for sure is to either try it or hook up a pressure gauge and let us know what the pressure between the two is. The same is true for hooking to the drain fitting of the heater. It'd be less permanent to hook up a pressure gauge there than between the heater and filter.

A picture or a diagram of your piping would help.

Then, today's more startling news: When the pool cleaning kid (who I believe is basically just taught "paint by numbers" with no real theory) shows up, he wants to add POWDERED (granulated?) chlorine to the Liquidator. ?!?!?! He says the owner "doesn't give him liquid chlorine." Pardon my ignorance, but what's the point of having a LIQUIDator if you don't use liquid chlorine?

So, QUESTION 2: Before I open a discussion with our pool vendor...is there any earthly reason you would want to run a Liquidator like that?

Absolutely none. The whole theory of operation for the LQ is that the concentrated liquid chlorine on the bottom diffuses into the less concentrated pool water on the top to provide the chlorine required for your pool.

Consider upgrading the liquidator to 3/8" tubing and fittings. There's a thread here about doing that. I did it on the outlet only and I can now peg the flow meter out above 5cc/min. I could keep my pool at shock levels if I ran it wide open. I normally run about 2.5cc/min

 

[Bama Rambler]

Also, while you're at it post a full set of numbers. Cause you know we like to see the numbers.

 

[landrick]

Heh heh. You guys and numbers! :-D Unfortunately, I don't have much to provide...I'm trying to leave the chemistry in the hands of the service company. (I did pick up some cheap-o test trips to at least get a vague idea of what was going on, but I don't know if the TFP community considers those readings to be worthwhile.)

In any case, to answer a couple of the questions: Yes, the LQ works fine when the tank is full (as it did when first started up.) Our pool system is pretty rudimentary: There's only one suction line (fed by a skimmer and the main drain, the plumbing for which combines somewhere underground) and one return line (that, again, splits somewhere and feeds three inlets in the pool.) In the equipment area, there's only "one up and one out" to play with. A couple of pictures are attached. (Now, be gentle, folks...I didn't build this, I only inherited it, about 10 days ago!) The structure is about 35 years old (although the filter is about 5 years old.)

Our service is twice a week, so they'll be back on Friday.

(The water in the photo is from a small leak in the return where a Liquidator was attached in the past (you can see the patch) and an equally tiny amount that's escaping at the seal on the Hayward.)

I tried to avoid including all the gory details of our situation: Apparently the pool was being maintained with tablets in the skimmer and/or weekly chlorine doses into the water. There was an ancient Liquidator tank installed, but with only the "Out" tube connected to the suction line; there was no pressure/feed. It apparently sat unused for some time, although it was full of a nasty brew (and the new pool kid topped it off with chlorine one day, which of course just drained right out.) When the installer put in the new tank, he dumped most of the contents of the old one into the new one, AND tossed in some powdered/granulated chlorine, which (a) introduced a huge batch of suspended solids to the new tank and (b) added a substantial ring of WS.

Part of why I didn't mention all that (other than to avoid boring you all) was to focus on our main problem: insufficient pressure to fill the LQ tank. I realize there could be some WS deposits in the inlet valve, but I imagine it's more pressure related: I briefly removed the inlet tube from the tank to see how much pressure was being generated by the pool return line, and I'd compare it to emptying a glass through a drinking straw. Not much.

I agree that the filter needs to be cleaned; it looks like it may be needed every couple of weeks. But it looks like the pressure may dwindle before the filter gets to the point where the service will agree to clean it (10 psi higher on the Hayward than when "fresh") so that's why I'm looking to maximize the pressure.

I thought we were home free when the thing worked well at first; I'm a little depressed that we may be fighting this pressure issue.

 

[JohnT]

The reason it isn't filling is because the dirty filter is restricting output flow, which reduces the pressure in the plumbing between the filter and the pool.

You may either need a larger filter, or the grids may need soaking or even acid washing to give longer cycle times. I'd also do some research on how much DE your filter requires, as it doesn't seem the pool guy has shown great judgement or knowledge to date.

 

[JCJR]

I agree with Bama's assesment. Your LQ is not getting pool water into the in line. There is not enough pressure to have fill water. Do you have the check valve between the return line and the LQ? The check valve can be closed, jammed or not enough pressure to open. Is that same "In" line clogged with WS (white stuff)

 

[landrick]

The reason it isn't filling is because the dirty filter is restricting output flow, which reduces the pressure in the plumbing between the filter and the pool.

Yeah, that's pretty much the conclusion I'd come to. Since it seems like the pressure is going to drop below the point where the LQ will function before the filter gets to the point where the service will agree to clean it, I was wondering if relocating the tap (to somewhere nearer the pump) would eke out any more pressure, and keep it running longer. It sounds like the answer is "hard to tell without trying it."

You may either need a larger filter, or the grids may need soaking or even acid washing to give longer cycle times. I'd also do some research on how much DE your filter requires, as it doesn't seem the pool guy has shown great judgement or knowledge to date.

In his defense, the *owner* of the company is very experienced and knowledgeable, but the kid he sends to do the work...not so much. In any case, that actually brings up another question (which might best go in another topic area...) Well, at the risk of hijacking my own post: I'm *also* still learning about the filter. He's cleaned it twice, by taking it out and hosing it off. Don't think he's ever backwashed it. Does that make a difference? (Agh, such a rookie question!) He's added DE both times, and I've subsequently seen a fair amount of it in the bottom of the pool on both occasions. I'll have to speak with the service owner about acid washing the grids.

 

[landrick]

I agree with Bama's assesment. Your LQ is not getting pool water into the in line. There is not enough pressure to have fill water. Do you have the check valve between the return line and the LQ? The check valve can be closed, jammed or not enough pressure to open. Is that same "In" line clogged with WS (white stuff)

I had to remove the check valve right from the start, because the tank got no flow at all with it in place. I've examined it for WS as best I can, and there doesn't seem to be a significant amount at the inlet.

 

[Titanium]

landrick,

pressure may dwindle before the filter gets to the point where the service will agree to clean it (10 psi higher on the Hayward than when "fresh")

Ummm, I'm confused. The pool service works for you. They should clean the filter by whatever criteria that YOU set up.

If they don't agree to this seemingly simple request, then it may be time to find a new pool service.

 

[landrick]

Ummm, I'm confused. The pool service works for you. They should clean the filter by whatever criteria that YOU set up.

If they don't agree to this seemingly simple request, then it may be time to find a new pool service.

That is an exceedingly good point....

 

[keithw]

You can definitely increase the inlet pressure by moving the input line after the pump and before the filter/heater. The heater drain plug is not recommended.

You can eliminate the check valve on the output side as well if you need more flow. These are primarily required for above ground installs.

I would also eliminate the pool company since it sounds like you are already more competent than the folks they send to you.

 

[Bama Rambler]

Understanding that you inherited this and there's not a lot you can do about it. The first thing I'd try is attaching the inlet of the LQ to the drain of the heater simply because it's the easiet to undo if it doesn't work.

If that doesn't work I'd then either try it on the horizontal line between the filter and the heater or on the pump discharge line. Putting it before the filter will increase the chance that you could possibly plug the inlet line to the LQ from trash going thru the pump but if that's what required there may be no alternative but to do it. That will certainly give you enough pressure to keep the LQ filled.

Also don't let them keep putting solid chlorine in the LQ. That only exacerbates the problem of "stuff" clogging the control valve, flow meter, check valve, float valve, etc..

 

[Water_man]

You hired a pool service company , a reasonable move for a condo assoc., who recommended a Liquidator but didn't make sure that it runs properly after installation, who doesn't supply liquid chlorine and wants you to add cal hypo instead. My suggestion is to dump them and find someone else who knows what they're doing. You can call Hasa, the LQ's manuf. for recommendations. They have a big presence in CA.

 

[landrick]

Thanks for all the comments; it's good to feel the support. Of course, nothing is ever simple. <sigh> The service guy added so much cal hypo (?) to the pool on Tuesday that the FC level shot up, and there was no need for the LQ for two days. In the meantime, for some reason, the Hayward filter gauge shows its pressure dropped about 3 or 4 PSI from one day to the next, apparently boosting the return pressure enough that the LQ tank filled up and then continued working properly when I opened its flow valve today. (Although I did have to tap on that pesky suction check valve to get it allow movement.) So, it's hard for me to rub the pool service's nose in it when the thing is actually functioning properly (although of course I'm going to insist that they start using liquid chlorine.) Taking it day by day for now...

 

[landrick]

Well, since closure is a good thing.... :-D

After my last posts, the pool service stepped up and said they would backwash the filter any time it needed it (actually, they said they'd do it weekly, which is actually far more often than needed, IMO) and they're maintaining the LQ properly. As a result, we've had no further problems at all with the Liquidator. It works as advertised, with no WS build-up, and keeps the pool chlorinated. Other than the fact that it wouldn't work with the inlet check valve installed, the closest thing to an issue is just keeping the pool chlorine level steady (a little tricky given the highly variable use of the pool, Cl level in the LQ, etc.) But that's something that we'll just have to keep working on.

Bottom line...had a few kinks to figure out in the beginning, but otherwise a good investment. Thanks for the helpful comments!

 

[Bama Rambler]

Thanks for posting back and letting us know. A lot of times we help with a problem and the OP never comes back and lets us know if it worked or not. Again, Thanks and glad it's working now.

P.S. Mine's working great since I upgraded the outlet line to 3/8".