SWG - No FC???

[RookWDW]

Hello all,

Thank you in advance for the help. I've been reading on here to get some information as a new pool owner, but I cannot figure out my issue.

I purchased a home with a 16x32 inground vinyl pool with an auto cover. Pool company estimated it at 18,000 gallons. I had a company come out to open the pool, redo the plumbing (it was a mess and the ballvalves were leaking), and install a saltwater chlorine generator, checkvalve, and anode. There is a 3 year old gas heater and a DE filter with new internal filter parts. I had the pool company open the pool also and show me the ropes a bit. First issue is that the prior owner used well water to fill the pool in the past, and I did the same this spring before I knew better. The moment they added chlorine it turned dark brown. After a week of a makeshift filter using a bucket and pillow filling, and some metal out product, the pool cleared up and looked good.

For about four weeks it was great, we had an early springs and the kids got several good swimming days of use. Then we had 10 days of cold rain where the pool stayed covered, save a bit of preventative maintenance on the cover. The pool got a bit cloudy and I took the water to the local store to get tested. I've had it tested several times and also have a few different test strips I use at home. Over the last two weeks the water is in good parameters, besides high Alk and no FC.

I had the SWG at 10% when it was running well. Once it showed 0 FC I upped it to 15%, then to 20, 25, etc and it's now at 50% which I know is too high.

Pool store tells me to shock it using the SWG, which turned the water brown again. I added more metal out product from the store that helped, but not completely, and the water still showed no FC. There had to be chlorine generated to turn the water brown, right? I called the pool company to come help and they confirmed zero FC, slightly high Alk, all else looked fine, except high phosphates at 250. They added "Stain Magnet" which turned the water clear in minutes, and added some phosphate remover (this was before I read on here about phosphates). There was a bit of slim on the liner walls that I brushed off and seems to be gone now.

Today, the water looks mostly good, very slightly cloudy in the deep end, possibly from the phosphate remover. But .... no FC. I backwashed as the DE filter was clogged and flow was very slow. I tried to use a cup to get water from the return line, which also showed zero FC. The SWG appears to be working as all the lights are green and there is no error code. The Pool guys took it apart and it looked clean save some debris but they cleaned it anyway.

I just cant figure out what I'm doing wrong here and neither the local pool store nor the pool maintenance company seem to have an answer. Both told me not to worry about CYA as the SWG produces chlorine non-stop - but the CYA is zero. Yesterday I did add a couple of chlorine pucks into a floater to attempt to help, and if nothing else to add some CYA.

Thoughts?

FC: 0
TC: 0.0
PH: 7.6/7.8
Hardness: 380
ALKALINITY: 180
CYA: 0
PHOSPHATE: 250ppb (yesterday before adding remover -but after adding Stain Magnet)
Salt: 3200
SWG is a Pentair iChlor 30 - rated to

I've read that metal out products can add phosphates, so perhaps that is why there were high phosphates to begin with. I also was told that metal out type products can use up free chlorine, but I had zero FC before I added the first round of metal out product. I also read that a SWG won't take a pool from 0 FC to the necessary 1-3ppm. Is that my answer that I simply need to add some liquid chorine to get it up to level? Is the level of metals, phosphates, algae such that it's using all the FC too fast? How can I verify for sure that the SWG is actually working?

Sigh -

 

[Texas Splash]

I just cant figure out what I'm doing wrong here and neither the local pool store nor the pool maintenance company seem to have an answer.

I can tell you ....... you're not testing your own water. The store and builder are some of the worst. #1 priority is to get your own TF-100 (link in my signature) or Taylor K-2006C test kit. Order one of those ASAP and post those numbers for us. Store numbers are often wrong and mean nothing to us.

Some basic notes:
- Read and save the link below. Tons of great info
- New water has no stabilizer (CYA) and it needs it or else the sun eats-up the chlorine quickly.
- I suspect you already have algae which is contributing to the FC loss.
- If you have not added any stabilizer or condition yet, add 30 ppm worth of CYA. If you use granular stabilizer, soak in a soak for a while to help it dissolve then squeeze it all out. Only go to 30 ppm for now as we need to test for algae later.
- Even though you have an SWG, get a couple gallons of liquid chlorine (or regular bleach) and add enough to increase the FC to about 3 ppm. Tomorrow and beyond until your test kit arrives, add about 4 ppm worth of FC each day. Use our PoolMath APP (Effects of Adding Chemicals) to help you with the proper amount.
- Don't try to mess with anything else at this point until you get your test kit, then we can really help you properly.
- Stay out of the pool store. They will drain your pocketbook and give you poor advice. We'll coach you through this. It's easy.

More to follow!

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[Texas Splash]

Oh, and welcome to TFP!

 

[RookWDW]

Awesome. And thanks. I do test myself but with the strips. So to confirm, even with a SWG I need to test for and have proper levels of CYA?

EDIT TO ADD:

Forgot one factor. We have well water as I said, but I have been filing any evaporation using a spigot that is after the softener and using a hose filter. Is that okay? I don't really want to bring in water for top offs.

 

[Texas Splash]

So to confirm, even with a SWG I need to test for and have proper levels of CYA?

Absolutely. For salt pools we recommend a minimum CYA of 70 to help preserve the chlorine generated between cycles

I have been filing any evaporation using a spigot that is after the softener and using a hose filter. Is that okay? I

Sure! Anything to "hopefully" lower the iron content.

But be advised test strips are just horrible. You can't trust their color shading or wide range of acceptable levels. A proper test kit is vitally importna.t Hope that helps.
.

 

[mguzzy]

Pat is on it.. I would like to add you have Iron in your water. This is common with people that fill from a well. Adding the sequestrant doesn't remove it from the water it only binds it to the sequestrant and then it goes back into solution with the sequestrant breaks down. So when you added the shock (which is chlorine) it caused the iron to come out of solution and change form so you saw it as brown/green in the water... I just wanted you to know the mechanics of what was happening there. Here is some followup reading for you on the metals in your water:

Metals - Further Reading

www.troublefreepool.com

Don't worry about the iron now, just follow Pat's advice for now and get a test kit and add liquid chlorine everyday to keep things steady. Test strips are not sufficient they are not accurate for what we do here, and prone to contamination. The TFTESTKits.net are the best of the bunch. Many of us use that one. With a SWG I recommend the TFtestkit-Pro with SWG option.

Oh and BTW.. Welcome to the Forum!

 

[RookWDW]

Thanks all.

I added a gallon of chlorine to start and will check on it later. For stabilizer, is granular preferred? I see online that is fairly reasonable cost wise. The local store had this instant stabilizer in liquid form that was $40 for a gallon. I didn't buy it yet as it wasn't what I read here ...

 

[Texas Splash]

For stabilizer, is granular preferred?

While you could use liquid gold (conditioner) at $40 per bottle, the granular is much cheaper at about $15 or so for 4 lbs. Just add the amount you need to a tube sock, nylon, or suitable material to hold the granules as they soak, then put it sock in a skimmer (don't totally block water flow) or hang near a return jet. After about 30 minutes you should be able to squeeze the stabilizer out like soft mush and be good to go.

 

[RookWDW]

Well, one bottle of chlorine, test strips says 3-4ppm I’ll have a test kit later to double check. But .... it’s brown ... again. Ugh.

any reason I can’t add more stain magnet? Or is there a permanent solution to get the iron out?

 

[mguzzy]

There are three ways to get the iron out permantly
Do a drain and refill, some people will do an AA treatment to get the iron stains off and put eh iron in solution, then a sequestrant to bind it and then drain and refill
Filter it out with Polyfill.. you have done that part already.. when its in the brown state it can be filtered
OR use a sequestrant that will create a by-product that allows the iron to be filtered out.. to my knowledge Metal Magic is the only product that makes that claim. I gave it a worl this spring and I think it worked, look for my thread.

The stain magnet is probably a typical sequestrant that binds to the iron but keeps it in the pool. I would try filtering it with polyfill and you can rinse it out and reuse it. Keep doing so until you get the iron out.. or most of it. Its the addition of chlorine that is causing the iron to change form. Here's my thread.

What I thought were old iron stains on my cartridge filters, is iron my water!

Hi all Amazingly I found no posts on the forum about this. So I was the victim of the dreaded Iron contaminated Clorox Pool Salt about 3 seasons ago. Apparently it was worse than I thought. There is a nice darker area in my mottled dark plaster in the deep end from salt additions from that...

www.troublefreepool.com

 

[RookWDW]

Ok,

I was able to get a Poolmaster 5 way test kit. I'll have to order a better one from Amazon.

FC - around 1ppm
PH - around 7.2-7.4
Alk - around 250

From test strips

FC - 3ppm
TC - 3ppm
PH - 7.8
Alk - 250
TH - 250

Water is now a deep brown.

Does the Bioguard 3 part iron stuff work? Erase Iron Stain Remover, Pool Magnet Plus, Sparkle Up. They claim that the Erase pulls stains from any surface, the Magnet plus causes it to combine into larger suspended particles to be filtered out, and the Sparkle up helps the filer filter out smaller particles. Real or bunk?

I tried the bucket filter trick for about a week. While it did appear to help, clearly it didn't work very well as it's still turning a deep brown.

 

[RookWDW]

BTW - Stain magnet, which has worked as a sequestrant agent well before, per the company is a SODIUM SULFITE and SODIUM ERYTHROBATE mixture.

 

[RookWDW]

So doing some reading this Pool Magnet Plus from Bioguard and Metal Magnet are both cheating agents and work similarly.

 

[Texas Splash]

You have a couple big things making pool management more challenging right now; the lack of a proper test kit and what appears to be an excessive amount of iron in the water. Your FC is actually low, so to have iron react in the water so quickly would indicate the iron content is much too high. Now if you haven't added the stabilizer (CYA) yet, the chlorine is exceptionally strong and will aggravate the iron that much faster.

But here are some key points to managing water with iron in it:
- You must have a good test kit (TF-100 or Taylor K-2006C). Knowing the precise FC and pH levels are critical in this case.
- Keeping the water algae-free is always step #1, regardless of the ice tea or other color presented by iron. Pool owners with algae must run the SLAM Process in its entirety first, then evaluate iron management.
- Once algae is out of the equation, as noted above by Mark, you have to remove iron stains around the pool (if present) via an Ascorbic Acid treatment. From there you have to decide if you want to continue adding a sequestrant on a regular basis to control the iron, or dumping the iron water and have fresh water delivered.
- For those with iron, there is no doubt polifill or other such type of filter can help, but it's by no means guaranteed to work in all cases.

The (chemical) key is trying to keep a relatively low/moderate FC level while avoiding algae, then also carefully managing the pH to prevent it from going too high. A high FC and pH will aggravate iron. The higher the iron content, the quicker those iron changes occur. Mechanically, the more iron you can filter out the better.

 

[RookWDW]

Good morning readings:

FC - 0.2
PH - 7.2
SWG still set to 50%
Alk - 250 ish
CH - 250

My kit will test for "acid demand" what the heck is that?

So, my uneducated guess is the FC is being used up by oxidizing the iron, which is why it is dropping even with the SWG being turned up so high? If so, then should I keep adding liquid chlorine (maybe less fast, like a 1/4 gallon an hour).

I have a bucket of chlorine pucks (from pre-SWG) with a couple in a floater to try and help. Pool guy said to put one in the skimmer basket, I've read elsewhere that is not a good idea. What say you TFP?

 

[Texas Splash]

I have a bad feeling that your consistently low FC and it getting chewed-up quickly is a result of algae, not iron. That's just my gut feeling. You could run an Overnight Chlorine Loss Test to confirm, but you don't have one of those test kits do do that test. The acid demand is just a way to manipulate the pH reagent to show you, along with that chart, how much acid is required to lower the pH to a certain value. I don't use that myself. The PoolMath (Effects of Adding Chemicals) will do that for you nicely.

 

[RookWDW]

Thanks Tex. I have not added the CYA yet. I'm heading to Walmart shortly to see if they have some in stock and to see if they have a Taylor test kit. I did add some of that Pool Magnet Plus as I ordered some a while back. It has reduced the brown color substantially, but the pressure on the DE filter has not gone up so my guess is it isn't filtering out as they suggest.

Can you do a complete drain and refill? Doesn't it hurt the pool walls or liner to do that? Or do you drain and refill at the same time to not let it drop too low? If this continues to be an issue I may do so. The intent is to use trucked in water to refill the pool next spring anyway.

I was also reading on TFP about the process of adding some chemical that causes the iron to drop to the bottom of the pool and then vacuuming it out. I need to read that more to understand, but if I have a week that we won't use it I could try that process.

 

[RookWDW]

I have a bad feeling that your consistently low FC and it getting chewed-up quickly is a result of algae, not iron. That's just my gut feeling. You could run an Overnight Chlorine Loss Test to confirm, but you don't have one of those test kits do do that test. The acid demand is just a way to manipulate the pH reagent to show you, along with that chart, how much acid is required to lower the pH to a certain value. I don't use that myself. The PoolMath (Effects of Adding Chemicals) will do that for you nicely.

Yesterday there was a slight clear film on the walls of the pool that I brushed off. There has not been any green tint to the water. I have also never added any type of algaecide besides chlorine.

 

[Texas Splash]

Your local Walmart may have stabilizer. If they are out, check Home Depot. As a last resort, you can buy granular stabilizer from the pool store, just ignore everything else. Locally, no one will have the TF-100 kit, that has to be ordered (link in my signature). I doubt anyone will have the Taylor K-2006C either as most people order that online. Your local pool store might have the Taylor K-2005 called a Deluxe Kit or something like that, but it does not have the FAS-DPD (powder & drops) we use for precise FC testing. Doing a 100% drain is almost never recommended unless an owner knows the ground is stable (high water table) and the pool shell will not move or liner pull away if applicable. In those cases, we say to lower no more than about 18 - 24 inches to help keep everything in-place.

 

[RookWDW]

Thanks. I think I just need to figure out how to manage the iron this year, then next year I'll truck in water and dilute the issue and hopefully in a couple years it will be completely out of the water.