Iron Issues

[357]

I've read a ton before posting but I don't have a proper test kit yet. I've been using some HTH 6-way test strips. I know they are innacurate and I just ordered my TF100 kit. I recently had the valve on my easy-set inflatable ring pool. It was 12' x 36" and wouldn't hold air due to a crack in the valve. So, I bought an 18' x 48" ultra frame Intex. The first year we filled the easy-set pool I made the mistake of using a source that bypassed our water softner (well water with iron). The water was clear but tinted brown. When I added chlorine the iron began to fall out of solution and collected in the filter and pool floor. After a few days, a lot of chlorine and frequent filter changes/cleanings, water clarity was perfect. The following year I filled from an source that is fed from the water softener. That time water was clear before and after adding chlorine, and overall I had no issues. This year I setup the larger pool and filled from the same "softened" source. I stopped a couple times, added salt, regenerated the softener (which is much larger/more expensive than the box store type) all in the hopes of avoiding iron issues. Yet once filled the water had a green tint to it. Nice and clear but tinted green. The old pool had a white bottom which made determining color/clarity fairly easy. The new Intex has a blue patterened bottom. So, I'm guessing the water was more likely yellowish-to-light brown. I thought I'd follow the same patter as previous years and added chlorine via 1" Tri-Chlor tabs. After reading some on TFP in the past I knew I needed to keep an eye on CYA levels so I also used some 8.25% bleach along the way. The pool is not quite as level as it should be. This allows the pump jet to break the surface of the water a bit. I know from reading other TFP threads that this can elevate pH levels and I've been seeing that. To counter it, I've been using Muriatic Acid. Despite reading about a few other folks pools clearing on their own, mine did not. I ran the pump 12 hours/day and cleaned the cartridge daily hoping to find iron falling out of solution.

I read the metals thread and ordered some Jacks' Magic The Pink Stuff. Per what I had read I waited until FC levels were low and I added 10% Algaecide (non-copper version that I belive was called linear polyquat in one thread) and waited for FC to drop to 0. Once there I made sure pH was around 7.2 using MA. Then, given the pool calculator shows my 18' circular pool at 4' deep holds about 7600 gallons, I added 3/4 of the quart. The bottle says it'll treat 10,000 gal so my math is close. The pool color has improved but not cleared entirely. Since adding the pink stuff I'm seeing yellowish-orange in the filter. I clean the filter twice per day via the garden hose and I've kept the pump running 24/7 for a few days now. The water is now a blue-green or turqoise like color.

Here's a pic from this morning.


This evening the pH was up a bit so I added more MA and waited for it to come down. Once it had I added the remaining 1/4 (8 oz) of the pink stuff. I've read that I'll need to keep adding sequestrant over time to maintain levels to keep the iron in solution. However, it seems to be falling out of solution and depositing itself on the filter. I haven't been in the pool so I guess it's also possible some has settled on the bottom giving me a false sense that the clarity isn't improving as much as I'd thought.

I'm wondering what to do next. My FC level is still at 0 and I'm sure the Algaecide is the only thing keeping me from a full bloom. It kind of makes me nervous. Can I start adding Chloring and bring it to recommended levels or should I continue focusing on filtering out the iron, waiting until the water color returns to normal? Also, should I keep people out of the pool right now or is it OK for the kids to swim? My little ones are 7, 6, and 16 months (obviously he only goes in with me or mom).

Related info:

Total Hardness = 0
FC/Bromine = 0
pH = 7.2
TA = 120
CYA = Not really sure. I did use some Tri-Chlor originally but I stopped over a week ago. At times this appears to read 0 on these strips and other times it seems the color that indicates "30-50".

Thanks for this great site. I'm on my way to being a true BBB practicioner. I can't wait for my TF100 kit to arrive so I'm not guessing anymore.

P.S. I have more pink stuff on the way as well.

Thanks,
Mike

 

[357]

Adding the remaining pink stuff seems to have improved the clarity even more but it's not quite clear yet. I think I've still got a bit of iron left. I'm sure adding more sequestrant will help, when my resupply arrives.

However, my question of when to chlorinate remains. Do I need to wait until I'm finished dealing with iron or can I bring FC up to recommended levels now? It seems the weather is keeping the other question moot for the moment. But it would be nice to know if I can let my kids swim or if they should be kept out until FC levels are at recommended levels.

 

[357]

Anyone?

 

[chem geek]

The point of having the pH be low is to remove stains and keep them from redepositing when you add chlorine. Once you've added sequestrant then the risk of staining is lower though not zero since you've still got colored water. If you are concerned about algae growth starting, you can use Polyquat 60 if you haven't done that already. I think you are probably safe to bring your FC up to recommended levels and add more sequestrant when you get it. Worst case, if you notice staining occurring again you can lower the pH back down.

 

[357]

Update:

Here's a new pic of my pool's much improved color:

Since the last pic I've added another 16 ouces of Jack's Magic Pink Stuff in two separate 8 oz pours. I've seen a lot of yellowish-orange pigment on the filter cartridge that seems to wash off easily like a fine powder. There also seems to be small piles of brown powder (like rust powder) collecting on the bottom of the pool. The pool came with some sort of vacuum I believe but I haven't tried it out yet. In previous years when iron oxidize out and settled like this I stirred up the sediment until it suspended in the water and ran the pump. After a few days of doing this it cleared and stopped settling on the bottom, I assume because it was caught in the filter. As I was waiting for my test kit to arrive I added a small amount of algaecide and the pink stuff mentioned, and kept cleaning the filter out with the hose. I didn't want to add anything else until I knew where I was.

So, I got my TF100 kit yesterday and got my first readings today. Here they are:

FC = 0
TA = 230
CH = 40
CYA = 0
pH = 8.2 or possibly a bit higher judging on the color scale
CC = I didn't test for it as the instructions called for adding drops until the solution turned back clear from the FC test. It was already clear so I wasn't sure what to do

So, based on those results and the pool calculator I need to add

46 oz of my 8.25% bleach to reach FC of 4
48 oz of 31.45 % Muriatic Acid to lower pH to 7.2
248 oz of Calcium Chloride to bring CH up to 260
41 oz of Stabilizer to bring CYA to 40

I have the bleach, MA, and Stabilizer on hand to meet these requirements. I don't have Calcium Chloride as I've never bought it before. Two questions. Where do I get CC and in what form? I believe it is sold at big box stores in the winter as something to de-ice your sidewalk or driveway. Not sure if that's the same stuff I'd need or not. Two, what order should I add these ingredients, and do I need to retest between certain ones?

Thanks for your help!

 

[357]

P.S. sorry for the poor lighting in the pictures. I can only get them in low light before work or after, unless it's on the weekend.

 

[357]

I did a little Pool School reading. Since my pool is vynl perhaps I don't need to worry about adding calcium via Calcium Chloride. So, which order to move forward in?

I was thinking:

1. Add 48 oz MA to bring pH back to proper levels (targeting the low end given my iron issues)
2. Wait 30-60 minutes and retest to confirm proper pH level
3. Add 41oz of stabilizer granules evenly around pool
4. Add bleach. Given the CYA will offset adding bleach, should I add more than the recommended 46 oz of 8.25% bleach?

Also, does this order make sense? Is doing this the same day ok?