Very high TA from well water, and high CYA and other issues.

[kmdigital]

Back story. I just bought a house with a pool at the end of June, and previous owner only used trichlor tabs and shocked weekly to keep algae at bay as he only ran FC of ~2 - 2.5. It wasn't used heavily, and with automatic, dark pool cover, he didn't have any major issues. I got the good TF-100 test kit in July, and the CYA is ~130 - 140 (using double and triple dilution), so a water change is warranted, probably next spring. I also need to deal with iron staining in the fiberglass pool as he used straight well water at 5 PPM iron to top it up this spring. He admits this was a mistake, as now there's some streaking in several areas from the iron. Plan is to deal with it using AA this fall after the water is < 60 and letting FC drop to 0 as it cools down so the AA works. Plan is to use polyquat 60 to prevent algae growth over the winter.

I've always had high TA, typically 200 - 220, and best I've managed was to get it down to 180 one time with several gallons of MA, but it went right back up with a refill. Yesterday I finally tested the well water, and the TA is 450 on the hard, high iron side and 500 - 550 after it goes through the softener, so now I know why it's always high, and it went back up so fast after I topped it off after draining about 10" out of it and refilling. The softened well water is ~7.1 - 7.2 PH, so the high TA doesn't seem to have a major effect on this reading, at least as raw water.

I don't have a problem maintaining PH, and it seems to hold steady where ever I leave it for several weeks at ~7.2 - 7.3 right now, so the high TA doesn't seem to cause any drifting issues. My reading indicates that primary reason for lowering the TA is that PH will tend to constantly drift upward, but it doesn't seem to be an issue with the TA I currently have. In fact, I used about 3 gallons of MA to get it down somewhat, and aerated the dickens out of it for about 4 - 5 days a month ago by running the pump 24/7, and the PH wouldn't come back up with the aeration. The MA dropped the PH to ~6.9 and the only way I could get it back up was with Borax. I made PVC return aerator as pictured on here by someone else to spray the water and left the cover open. All it did was turn the water foamy and collect lots of debris and leaves that I don't normally get, but the PH did not come up with days of aeration, so I gave up and used Borax to bring the PH back up to where it should be, and it seems to stay there very well and doesn't drift up, at least not quickly.

I was going to drain and refill with soft well water next spring as needed to get my CYA down, but now I'm not sure if that's a good idea, given the extreme TA readings. Given these values, there really doesn't seem like there's any practical way to ever get and keep the TA down at the recommended levels, as it would take extreme amounts of MA to bring it down. And I suspect, it would be a struggle to keep it there given it would increase again any time water is added. Of course, this would mostly be in the spring when opening the pool, as there's not much need to add water otherwise.

The question is, how critical is it to control the TA and keep it down as much as possible? It seems that the only way I could get and keep it down is to have replacement water hauled in, and I have no idea what that would cost, but expect it would be rather expensive.

What would the experts suggest? I've read where some people have had the CYA drop significantly over the winter, but seems the consensus is that it was either bacteria or dilution that caused this, and hoping for bacteria to lower it probably brings it own potential set of problems. If I drain and replace ~70% of the water, the TA will go way up, probably ~400 - ~450 if I use soft well water. Is this going to cause problems, or what are the recommendations? It would take an exorbitant amount of MA to try to bring this down to say 120, and I expect it would be a constant battle trying to keep it there.

And I guess adding melamine to the water to coagulate the CYA and then filtering or dumping it isn't a good idea either, and might require completely draining the pool from the mess it could cause. I've considered it, but after reading some more, decided I shouldn't try it.

I'm a bit stumped as to the best course of action at this point. Right now FC = 11, CC ~0.25, CH 200, PH = ~7.3 and TA = 220. Suggestions?

 

[JohnT]

Re: Very high TA from well water, and high CYA and other iss

To really answer, we need to know where you are and what the CH of your well water and pool water are.


My well water is over 450ppm TA, but I keep the pool TA down in the 100ppm range. The easiest way to lower TA is to replace the pool water with rain over the winter.

 

[Isaac-1]

Re: Very high TA from well water, and high CYA and other iss

Like JohnT said we need more information, if your in an area with a reasonably amount of rainfall, can you set up a rain catch system to refill and maintain your pool water level without relying on the well? This may be gutters ran to a barrel with a tap on the bottom rigged as a basic sand filter, tarps to direct rain into the pool, etc.

Ike

 

[kmdigital]

Re: Very high TA from well water, and high CYA and other iss

My well water is very hard, at a CH of ~600, with 5 PPM iron, so straight well water is a bad idea. Pool CH is now 210, so must have mostly been filled with soft water, or PO had it trucked in, though I doubt it. I do know it was installed in Dec, so I don't know how he filled it in the middle of the winter, but may just have used a garden hose running for days.

I'm in northern Indiana, so way below freezing in the winter. I hadn't thought of using rain water, but this sounds like it might be the most viable solution, dumping rain water into the pool prior to winterizing it via a rain barrel of some sort. I would probably only want to do this in Oct, and maybe early Nov, keeping an eye on the weather for any unexpected cold snaps.

I have a good sized roof about 20' from the pool, and if I set a rain barrel on this gutter, and put in some sand in to filter it, I could tap off the bottom and let it drain into the pool. Not sure if a garden hose would suffice, as it probably wouldn't drain fast enough and then the barrel would overflow, so would need something like a 1-1/2" - 2" hose under the edge of the pool cover and even this might not keep up during a hard rain. Should the hose go to the deepest part of the pool or should I should leave it right at the surface? Since I'm not there a lot of the time, I would either need to pump it down somewhat, before it rains and let the rain refill it,or just let it overflow as it rains and thus dilute it. This might be the easiest way, especially since it's a little out of level and the lowest end is where I would want it to drain out anyway.

The main thing is I could only do this until the I winterize it, and then let it go for the rest of the winter and continue this process in the spring, say April or so prior to opening the pool.

The other option might be pumping water out of the lake, as it's only ~40' from the pool. I definitely wouldn't want to pump now as it has algae in it, but I'm wondering if this might be a be a good solution next spring when the algae should be dead, though I don't know if it actually dies over the winter. This would certainly be a the fastest way, as I could get a good sized pump that should be able to keep up with the pool pump, and it wouldn't take more than a couple of hours to essentially drain and refill the pool with lake water. I would want to check the CH and TA of the lake water, as it might be high too, though I'm guessing that in the spring after the winter snows and spring rains it shouldn't be real high.

On other idea, that probably wouldn't work, is to get a long fire hose and permission from the town to fill from a fire hydrant that's about 400' away. I'm just outside city limits, so I'm on a well, but city water is not that far away, but rather doubt they would give me permission to use this, and I don't know what this water is like either as haven't tested it.

Thoughts?

 

[JohnT]

Re: Very high TA from well water, and high CYA and other iss

IMO, lake water is your answer, and spring would be the perfect time to do it. You can get a filtered intake screen at Lowe's to keep the chunks out.

IMO you don't want any part of 600ppm hardness/450ppm TA water with iron in your pool. The headaches are far greater than a little algae at a time of the year when you are probably going to have some in the pool anyway. Trying to fill with softened water will require frequent regeneration and won't improve the TA at all.

My pool is the same size as yours, and I keep my TA pretty low by avoiding water additions as much as possible. I have a mesh winter cover to let in all the rain we get over the winter as well. I generally only backwash the filter when the pool has excess water in it from rains to save what I can.

 

[Patrick_B]

Re: Very high TA from well water, and high CYA and other iss

Hi kmdigital,

Welcome to TFP!

You are getting great advice from the best we have here already, and I just want to add one thing to the discussion so far. Stay AWAY from the hydrant water. Depending on how long it's been since purged, it may be super loaded with a huge amount of Iron. A lot of sediment is likely too, but Iron is almost certain to be very high. Almost anytime you see one of these opened the first color you see is burnt, rusty, brown-red. That is from the water rusting/dissolving the underground piping while it sits there stagnant. Just my 0.02 for the moment. I would go with the Lake water if it were me. Great idea there if you can use it.

 

[kmdigital]

Re: Very high TA from well water, and high CYA and other iss

Thanks for all the advice, and that's what I'll plan for next spring. It was kind of an afterthought originally as I wouldn't want to pump it now given all the algae in the water, but it suddenly dawned on me this should be clear in the spring. If I pump before the boats get in the water and stir things up, it should be really clean. It's about 6' deep off the end of my pier, so pumping off the surface should be exceptionally clean this time of the year as long as it hasn't been stirred up from recent rains or boat traffic.

 

[Patrick_B]

Re: Very high TA from well water, and high CYA and other iss

Well, if it were me bringing Lake water, I would complete a very thorough SLAM procedure on the pool after I filled it. I really encourage you strongly to do that. It cannot hurt at all and would be a very prudent thing to do, no matter the condition or clarity of the Lake water.

 

[kmdigital]

Re: Very high TA from well water, and high CYA and other iss

Well, if it were me bringing Lake water, I would complete a very thorough SLAM procedure on the pool after I filled it. I really encourage you strongly to do that. It cannot hurt at all and would be a very prudent thing to do, no matter the condition or clarity of the Lake water.

Understood that, just to make sure all nasties have been killed off, even if it's in the spring. Thanks for the suggestion.

 

[Patrick_B]

Re: Very high TA from well water, and high CYA and other iss

Sure thing.