Universal 40 cell goofiness

[Rattus Suffocatus]

So, about five weeks ago I finally had to clean the cell again... I made it a LONG time this time after finally getting the TA under 100 in the pool (like 10+months)... that was the 3rd time in 2.5 (less than) years since I first put it in. I guess I didn't get it completely clean as I needed to do it again in about a week. I do honestly think I missed a glop of junk the first time.

My cell since after the first time never tripped the cell maint light. It's always faded away dropping to "Lo Salt" instead of saying "Cell maint" except for the first time I needed to clean the cell.

The second cleaning of the cell this time, I also increased the flow a bit on the pump on the low (VSP) setting just in case that was an issue. I noticed that it was reading right but intermittently would show a lower reading. But then I had to go to the Midwest for three weeks... now after about a month I am seeing a readout that is 900 PPM less than the K-1766 shows. (pool tests at 3400-3600, probably 3500 PPM actual-- two different kits.., but it's reading 2600 PPM)

So it looks like it needs to be cleaned again. But honestly I expect to see it mostly clean when I pull it.. this is waayy to soon. The water chemistry is okay to good, though I am up to about 600 CH (probably over but not 625 yet), so a partial exchange is in my summer future. CSI is slightly negative and all that was low was CYA but more has been added. The monsoon rains tend to wash out some salt and CYA every year in June/July...

It's still generating chlorine and even the volts and amps pulled look about right.. it's just that the self estimate is now about 900 PPM low...

So do you experts think the cell is going bad prematurely (I do, actually) or that I need to go in with my fiber optic USB scope and see if something plugged, or simple try to clean it again? Can I run it flipped around (upside down) for awhile (in a vertical setup) to see if I can backwash it out?

The manual states (without specifying the strength of the acid, so I assume 31.25%) four to one for the water to muriatic solution. I have been cleaning it 10:1 every time and that seemed to work. Is there a benefit to going that much stronger? I was trying to preserve the life of the plates.

But normally a cleaning and it's right back to new...

So I dunno? What else can I try before calling DSP/Circupool? I really am not in the mood for a $400 expense right now....Wasn't expecting that with a 40K unit on a 15K pool until at least year five... Let me know what tricks I can try before buying a new cell at year 2.25 out of 5.

Even if this is the case.. it saved me last year and the early part of this year due to the family disasters I had, so I still would probably buy it again despite this issue...

Now the pool itself? Nope. Never again....

Edit: fixed a couple of errors like acid to water instead of water to acid, and the size of the pool. Posted initially in a hurry....

 

[mknauss]

That SWCG uses the same system as the Hayward, where it does not measure salinity, but performance of the cell to create the salinity. So 2600/3500 is 75%. So once that gets to 70%, the cell is done.

If the weaker acid cleans the cell, all the better. Not sure on that unit if you can look through the cell or not.

 

[Rattus Suffocatus]

No, you can't see through it.. it's encased in white PVC. And okay on the cleaning strength.. I figured that weaker was better. I'll pull it on the weekend and do a really good inspection on it. I'll be rather disappointed if all I'll get out of it is 1/2 the rated life though, especially on a 45K cell on a 14.5Kgal pool. It is set for 40% right now and runs about 8 hrs a day. So it's kind of loafing on a pool that size.

I guess I'll contact Circupool, I should get at least 25% off of a replacement if that is the case according to the manual. I guess in the meantime, since I have a water exchange coming up probably in the fall for the CH being at 600+ now, that I could raise the salt level a bit to the cell's max of 4000 PPM instead of the 3500 I have now. Maybe that will give me just a little more time and leeway.

My pool and testing has been lax by TFP standards in the last year or so but honestly I have the best looking water in the neighborhood... so I was as tight as I could get to their standards listed in the instructions with Tucson water. Likely more tight than most people and services would be despite me not doing 100% of TFP testing in the last few months. (The water was pretty good on the sort-of open loop I was doing due to lack of time, honestly, when I did do a full test with new chemicals.) TA is an issue and CH is starting to be one.. but I did get TA under control....TA control is difficult on our water... honestly if the dogs didn't drink the water I would have used borates.

It's odd.. it just went from being fine to doing that all of a sudden. I would have expected more degradation time than that...

 

[Rattus Suffocatus]

Hey, you wouldn't know anything about the difference between the Si and Ul cells, if any? I thought they were basically the same unit but Si cells are $100 cheaper for some reason from Circupool. I do need to check that the control unit thinks it's a "f-15" cell type though when I get home..... maybe it got bumped into a different cell type...

One of the reasons I ask this, as terrible as I am, is that there is an aftermarket for the si45 cell "f-15" type that's actually clear... I might take the potential hit and experiment with it instead as it's a lot cheaper too....even figuring in a discount for the warranty....

 

[Rattus Suffocatus]

I suppose I might also try the cell recalibration procedure that is well documented with the Hayward T-15... I'll update if it even exists in the Circupool unit... If I can kick it up a couple of notches it might last a bit longer.. it's always read a little low....

 

[poolurker5]

Hey, you wouldn't know anything about the difference between the Si and Ul cells, if any? I thought they were basically the same unit but Si cells are $100 cheaper for some reason from Circupool. I do need to check that the control unit thinks it's a "f-15" cell type though when I get home..... maybe it got bumped into a different cell type...

One of the reasons I ask this, as terrible as I am, is that there is an aftermarket for the si45 cell "f-15" type that's actually clear... I might take the potential hit and experiment with it instead as it's a lot cheaper too....even figuring in a discount for the warranty....

I also have the universal 40, and the control screen also is "f-15". Will be following this to see how the off-brand replacement cell works.

 

[Rattus Suffocatus]

Will do. I need to try to see if I can't get it working better (it's still producing chlorine, so...) this weekend before I start to talk to Circupool or buy a cell elsewhere, but the only commentary to the negative that I am reading about the aftermarket cells, is that they tend to read a higher salt level than actual. So the opposite of my issue now.

That's only been with people using the real Hayward unit. Supposedly if you lower the actual salt level to the low end they work fine. I wish there was a little more detailed information out there on how that all works.

I've thought that an open source Arduino control box could be a great project for someone, honestly.....Because you could probably build that up with an aftermarket cell for 1/2 the price of a new unit and potentially have the choice of many different cells....

 

[Rattus Suffocatus]

So, I had the thing "Lo Salt" on me again this morning, and I just decided to be about 45 minutes late to work today. I completely disconnected the cell (I usually clean it outside near the control) took it inside as it was obviously scaled up again, but this time only after about 3.5 weeks or so. When I was gone, my kids didn't add acid like I asked (nor clean the kitchen or take the trash out. Society is doomed going on.), so the pH and CSI did creep up a bit, so it's likely that contributed. But it wasn't bad enough that the cell scaling up in less than a month should have happened.

I put the cell under a strong light and made the executive decision that an acid bath alone wasn't going to cut it. I cut the "floppy" tip off of a long Ty-Wrap cable tie and used the rest of it to scrape the calcium scaling out. I mixed the water to acid mixture at 6:1 this time. I used the Ty-Wrap to scape off all traces of calcium by doing it before and after the first bath, and did a rinse and second bath until there was almost no activity (bubbles).

In between the stronger bath and physically scraping every thing out, when I reconnected the cell, if anything it is reading high now. So probably getting in there with the plastic Ty-Wrap is needed every third cleaning or so. I suspect even though the last two times I cleaned it it looked clean there was still some scaling hidden deep within the cell and plates and that provided a nucleation point for new scaling on the cell quickly.

The newer cell designs that allow you to remove the plates probably have an advantage here. It's VERY difficult to get at and to see the plates on this older design.

I'll update if there is a further issue in the next several weeks. I do not believe that if I had not physically got in there with the plastic Ty-Wrap that I could have properly cleaned this cell this time. But the controller seems much more happy. I wish there was a way to reset the moving average... I guess tomorrow I'll see if that starts coming up properly.

 

[Rattus Suffocatus]

So-- the cell thinks the salt level is dropping again. (It went shy of 2 weeks or so at the correct reading according to the K-1766) I did a full test this morning and it's not.. but inexplicitly my CYA level dropped again. So I will be adding more.

The other thing that changed a lot in the last week or so is my CH level went up to 700 from 600 a couple of weeks ago. So I suspect that is why the cell is scaling up even though I have the TA down to 60 and CSI -0.22 or so now-- I have been rather aggressive with the MA in the last couple of weeks. Been going through a lot of it and its been hard to find in the stores lately so I am a bit concerned. I don't have a heater so running it more negative I don't think will be harmful.

So I suspect it's time for a (partial) water change. Is there a guide somewhere on the proper way to do this on a plaster pool in the desert? I will try to fill with water from the water softener, but I suspect it might be time to try to figure out a path to get to having a softener in line with the pool in the future. Either a long run for fill around the entire house or a second softener mounted outside in my "shed" that is the equipment area. Suggestions are welcome.

It could be the cell going bad. If so I guess cleaning it once a month until next season is probably not going to hurt it much more than it is if that is the case.

 

[mknauss]

Follow the water exchange in Draining - Further Reading

 

[Rattus Suffocatus]

Follow the water exchange in Draining - Further Reading

Thanks... for some reason I wasn't finding it. I suppose late fall or next spring, probably too hot for the plaster now. Seems like it's a bit of a pain....

 

[mknauss]

Exchange does not expose plaster.

It takes time, but little effort.

 

[Rattus Suffocatus]

I guess if I used soft water that might work.. It'll be at least two weekends before I can get to it though.. I'll have to start doing some testing of the fill water sources (before and after the water softener) and also some math. We used to have a quarterly report from Tucson Water (I am on a separate system from Matt and Tucson but they run it down here) -- that had useful info like varying CH levels by month. But it appears that those have disappeared from the internet, sadly. It does vary a lot here as they mix sources of water.. including Colorado River Project water that is more like rock dust than water... very high CH levels in that... which is why Phoenix is worse most of the time.

I'm assuming if I do it that way I'd have to calculate with a running average of some sort.... Maybe I can run it by day over a three day weekend or something and recharge the softener every night. Gonna be an interesting experiment regardless. It only took about 20 hours to fill the pool in the first place so I'm probably obsessing anyway... Dropping the level down a bit for a couple of hours would let me clean the tile line though.. so there is a fair amount to consider here...

 

[mknauss]

That rock dust river is a 1/4 mile from my house.

 

[Rattus Suffocatus]

That rock dust river is a 1/4 mile from my house.

Yeah.. I've been up that way a time or two! I suspect a lot of it is from the aqueducts they use to get it down to us, and not only the river. Luckily there is still an adequate amount of well water most of the time here.

I usually say if you like rocks, AZ is for you. Tucson even has that big rock and mineral show every year....

I have to admit that that little section of AZ (US 93 IIRC, becomes I-11 in NV) between Kingman and Las Vegas NV is one of the most beautiful areas in the state of Arizona. Big Sandy (rock dust?!?) River IIRC... Been all over NV and all of AZ except for Yuma (been as far west as Organ Pipe National Monument and Lukeville, AZ, tho.)

It's been a little less than a year ago since I stayed in Laughlin for a night....

My other house down near Sierra Vista is only a couple of miles from the San Pedro Riparian area. Riparian anywhere else simply means shoreline of a creek or river... but here to have a shoreline means there is water at the surface. So I imagine that those two are about a handful of rivers with water at the surface permanently here. Hopefully that stays the case up by you. The San Pedro flows south to north too. Summer storms go East to West here... a lot of weird backwards stuff here...