Switching from pucks to liquid, thoughts and insights?

rtilghman

Active member
Nov 19, 2014
43
Austin, TX
Not sure if Pumps, Filters... is the right channel for this, but didn't seem to be another clear fit. As the title summarizes, I've had an inline Pentair chlorinator since install (pucks) and I'm considering/looking at switching this over to a liquid set-up. Wanted to get advice/insight from anyone at TFP who might have experience with this?

To provide some more context, I have a ~15k gal in-ground pool in Austin, TX. Equipment is mostly standard Hayward gear with some odds and ends mixed in (like the Pentair chlorinator). The pool has some overhanging/nearby tree cover, not a lot but enough that with drop and wind I get a good amount of stuff in the pool. The pool is also open year round (Texas), which leads to some secondary challenges in terms of chemistry. I have two problems that are driving this change.

1) Algae is a CONSTANT battle. Even with constant chemistry monitoring, regular brushing (including a metal brush on the plaster itself), and full blast shocking as needed (zero chlorine mvmt over multiple days) the algae returns.

2) I have to annually manage CYA due to the year round pool (no water replacement). Typically this means that sometime in May/June I switch to liquid for a 3-4 months (manually), enabling the CYA to break down in heat at a rate of about 10ppm / month. This is just irritating because I'm lazy.

I also feel like, for whatever reason, the pucks are less effective than the liquid. Whether my pucks are old/weak (I bought the lg bucket last fall, so should be fine) or pucks are just generally less effective I feel like EVERY time I switch back to pucks things get out of control, even if I'm running my chloring at 5-6ppm (with little/no pool usage).

So, does anyone have experience with going to liquid? A recommendation on a liquid chlorinator? One challenge I face is pad space... my pad is very small, so I have to find room for it. Considering some kind of platform between the heater and filter (see photo) which I would obviously make stable, but not sure if that's safe/practical.

Thanks in advance for any help!

Best,
Rick
 

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Mr Bruce

TFP Guide
Mar 24, 2014
2,438
Greenville, SC
Even with a stenner pump you are going to have to mess with large quantities of chlorine. If you don't want to bother with handling liquid chlorine, it sounds like a salt water chlorine generator is your best bet.
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,694
Houston, Texas
Pucks add CYA. The more CYA you add the more chlorine you need. If you try to meet the need with more pucks or dichlor granules you are in an escalating cycle of increased CYA and decrease available chlorine. Could you post a current set of test results? We can advise you better when we have numbers to work with.
 

rtilghman

Active member
Nov 19, 2014
43
Austin, TX
Thanks for the responses. Responses below:

Even with a stenner pump you are going to have to mess with large quantities of chlorine. If you don't want to bother with handling liquid chlorine, it sounds like a salt water chlorine generator is your best bet.
I don't have a problem handling LC (large or small quantities), I just don't want to have to go out and do it daily or every other day or so to maintain a proper level. SWC is a non-starter for me for numerous reasons including 1) stone deck, 2) nearby metal roof, 3) nearby plantings, 4) no interest in the added cost of the SWC equipment and overhead.

Pucks add CYA. The more CYA you add the more chlorine you need. If you try to meet the need with more pucks or dichlor granules you are in an escalating cycle of increased CYA and decrease available chlorine. Could you post a current set of test results? We can advise you better when we have numbers to work with.
Yep, intimately aware of the intricacies of puck chemistry, CYA, etc. I was actually the first guy I know of to post some kind of definitive info to TFP about the breakdown rates of CYA, at least for my region/area (there wasn't any information in the site about it previously, which was frustrating). Basically CYA breaks down - at least at higher water/ambient temps - at about 10ppm / mo. Basically I've got a process to manage this and keep my CYA in check, I just don't want to have to deal with it, and a liquid system eradicates the problem entirely. As for my chemistry, it moves (depends on temps, season, etc), but in general: Calcium = 350, PH = 7.4, Alkalinity = 110, Chlorine = 4.

Basically I'm looking for 1) liquid chlorinator recommendations, 2) conversion insights and experiences, 3) gotchas or insider knowledge (typical burn rate, maybe weekly comparative cost if anyone has run those numbers, etc).

Thanks!
Rick
 

Mr Bruce

TFP Guide
Mar 24, 2014
2,438
Greenville, SC
Your pool already probably has salt around 1000ppm. I've never seen reports on here of the slightly higher salt level required for a SWCG damaging decking, roofs, plants, etc.

Also the cost is basically a wash given that you are paying for all your chlorine up front.

I'm not trying to sell you on a SWCG, fwiw. Just commenting :)
 

rtilghman

Active member
Nov 19, 2014
43
Austin, TX
Your pool already probably has salt around 1000ppm. I've never seen reports on here of the slightly higher salt level required for a SWCG damaging decking, roofs, plants, etc.

Also the cost is basically a wash given that you are paying for all your chlorine up front.

I'm not trying to sell you on a SWCG, fwiw. Just commenting :)
Haha, no worries, I hear you. That may be true in terms of the default salt levels, but no one around here (pool installers) will install SWCG with the context I described. My neighbors across the street just put their pool in (motivated by our pool) and the installer refused to do SWCG due to the same factors (especially the Leuder limestone deck, which is the same as what we have).

So, my solution is either pucks (current) or liquid (potential), I just need to figure out what I'm getting into if I pull the trigger on liquid. :)

-Rick
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,694
Houston, Texas
There is a little more maintainence with a liquid chlorine dispenser. They can build up salt in the small tubes and fittings, so you have to clean them or replace parts periodically. Hard water may make them scale up quicker too. A few years back we had a lot of liquidator and stenner pump threads. I don't recall any that are currently active, but you can google search the site for them. I know a lot of the issues pro and con have been discussed before.
 

Rwmiller80

Active member
Jun 2, 2019
25
San Jose, CA
Looking at the photo in the original post, you have a UV system installed. If that is no longer functioning / you don't feel it is useful, you can remove it to gain space for your liquid chlorination system. That is my 2 cents worth.

Bob
 

rtilghman

Active member
Nov 19, 2014
43
Austin, TX
There is a little more maintainence with a liquid chlorine dispenser. They can build up salt in the small tubes and fittings, so you have to clean them or replace parts periodically. Hard water may make them scale up quicker too. A few years back we had a lot of liquidator and stenner pump threads. I don't recall any that are currently active, but you can google search the site for them. I know a lot of the issues pro and con have been discussed before.
Awesome, thanks for the insights! I've basically found the Hayward system (which seems to require the chemical control unit/component for the hayward panel which I think I'd need to add to my current Hayward set-up), the Pentair system (which seems to need control but which I'm kind of unclear on the details around), and the gravity based Liquidator (which seems to solve some of the maintenance issues but also seems kind of... nuanced). The Liquidator seems like the most straightforward solution, though I do like the idea of going Hayward and having full integration/control.

The Liquidator

Hayward

Pentair

Looking at the photo in the original post, you have a UV system installed. If that is no longer functioning / you don't feel it is useful, you can remove it to gain space for your liquid chlorination system. That is my 2 cents worth.

Bob
The UV system is still operational... I maintain it, and I refurbed it to keep it in shape (new power converter, etc). I'm sure it doesn't do a lot with the amount of water I'm running and the speeds, but it does SOMETHING, and in a year round pool with plenty of bio debris I need every bit of cleaning power I can get. So, I'd prefer to not kill it. The best solution I think is just to go up, just worried about that much weight - in chlorine - up high. The sun exposure is also a little bit of a head scratcher... the Liquidator doesn't look particularly "UV protective".

Thanks,
Rick
 
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jmhjgh

Well-known member
Oct 20, 2011
182
Minnesota
Out of curiosity, what levels of CYA do you try and maintain in the Texas sun? Your earlier chlorine level of 4 would indicate a CYA in the 20-30 range, but I would think yours would be higher running pucks. If your CYA/chlorine relationship is correct you should not be battling algae.
 

rtilghman

Active member
Nov 19, 2014
43
Austin, TX
Out of curiosity, what levels of CYA do you try and maintain in the Texas sun? Your earlier chlorine level of 4 would indicate a CYA in the 20-30 range, but I would think yours would be higher running pucks. If your CYA/chlorine relationship is correct you should not be battling algae.
I try to keep it to around 50, and I run the mins on FC because I don't like high chlorine levels generally with the kids. Min for 50 according to TFP's CYA charts is 4. However, it's worth noting that even when I DO run it higher on pucks (I've kept and run it at 10 with a CYA of around 50-60) the algae has still come back, and that's after aggressive brushing (plastic and wire) and a full shock.

EDIT: I didn't mention it because I didn't want to unpack it, but I also think the TFP numbers are a little high. The figure I typically work off (found in various resources) is 7.5% of CYA levels, which in general are a few points lower for targets than the TFP numbers.
 
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Ironman92

Silver Supporter
May 11, 2016
22
Katy/TX
110275I have a 30 gallon stenner tank/pump that I use. I got it on sale for the same price as a 15 gallon system. It's nice to have the tank high, so I don't have to bend over to add chlorine. My system is hardwired into my sub-panel and I use the IAqualink to adjust my times. I usually keep less than 7.5 gallons of chlorine in here at a time, but could load up if I wanted.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
21,191
Laughlin, NV
The TFP recommended levels, the target range, is what you add to when you add your liquid chlorine. Then during the day, the FC lowers due to UV loss, etc. The goal is to never have the FC, in any part of the pool, drop below minimum. If you ride the minimum, you will drop below it. And algae can return.
 

Newdude

Well-known member
Jun 16, 2019
460
NY
I have 7 years with a SWG and a flagstone patio. It’s starting to show wear this year. 1/32 to 1/16 of an inch recesses and wavy lines. The tiles are close to 3 inches thick so it will probably take another 25 years to wear them down enough to need replacing. It actually gives the affected tiles some character instead of being perfectly flat. You have year round use in TX but I have snow and ice sitting on the patio for a month or so each winter so its probably similar in the end.
 
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