Will brushing and continued SLAM clean the stains?

[nykid]

Long long time lurker, 2nd or 3rd time poster as I continue to learn.

We moved and had a pool that went bright green after taking down a ton of palm and yucca tree overgrowth prior to moving in. Bunch of dirt, rocks, leaves, and sticks settled at the bottom for 2 months. Had pucks to help, but realize now it raised the CYA. Trying to course correct the CYA by mixing in fresh water.

I'm in the process of slamming, brushing, and vacuuming, and on day 5 now. Water is clear now, not cloudy. When I brush, there is still a slight cloud, so I know to continue the SLAM. Now that I can see the bottom clearly, I see stains. I keep brushing and it doesn't scrub off. See pic. (I'm cleaning the bag from polaris and not on, left dark spot is a leaf)

Do I need to drain/ acid wash? Or continue to SLAM / brush and it will go away? I read the forum and the net and not a clear answer. Thanks in advance.





FC - 13 overnight (from 28). I use 10% bleach to get to SLAM level every 3 hours during the day.
CC or TC - .5
pH - 7.8
TA - not tested due to SLAM
CH - not tested due to SLAM
CYA - 70

 

[mknauss]

The stains are either organic, or metal. If you have one of those pucks left, set one on the pool surface that is stained for 10-15 minutes, no longer. Does it remove the stain? If not, it is a metal stain. I doubt you have iron, so most likely copper. But try the puck first.

 

[nykid]

Thanks, Marty. I never considered it being metal. In our area, it is 50/50 ground well and mountain spring mix. To date I have refilled about 1.5ft of tap water. We have a slow leak and having that checked this Friday.

I tried the puck for 15 mins. Didn't see a change. I then took the puck and scrubbed another section and it helped. Of course, it could have been the physical scrubbing that helped a little bit. After this, I pushed the slam FC to 31 to see if it would help. Overnight drop was 1 to 2 ppm. Getting closer to OCLT target.

Should I get a Jack's Magic Stain ID item, or is there another recommendation?

 

[Texas Splash]

Should I get a Jack's Magic Stain ID item, or is there another recommendation?

To rule-out iron, try some crushed vitamin C tablets in a thin sock or nylon. Shoot, you might even be able to place a bare tablet on there long enough (before disslving) to see if there's a reaction. If vitamin c tabs remove the stain, it's iron.

 

[BassPlayingDude]

I had those same stains last year .. crushed up Vitamin C tabs in a sock made them go right away. Just be careful because the Ascorbic Acid will eat some of your chlorine.

 

[nykid]

Thanks for the recommendations. Tried some Vitamin C... the stains are iron. Going with the ascorbic acid treatment. After reading different threads, still confused about Sequestering Agents and something like CULater in the skimmer. So:

1) Do I use both at the same time? One to bind iron and keep from the walls (Sequestering Agents) and the CULater in the skimmer to hold onto the iron and toss the pouch after a months time of trapping the iron.
2) Both does the same. I need to just backwash out the iron after a 24-48 hour period.

 

[Texas Splash]

#1 seems more appropriate as each product serves a different purpose. The sequesraunt is a recurring treatment that simply binds the iron in solution to keep it from precipitating out. The CUlater is advertised as polymer product that mechanical attempts to "grab" the iron particles. Nothing wrong with using them at the same time as far as I am aware of.

With backwashing and exposure to chlorine, you can expect sequestraunts to eventually weaken and require replenishment. Try to keep the pH controlled since a high level of pH aggravates iron - so does excessively high chlorine.

Also see: Stains in Your Pool - Trouble Free Pool

 

[BassPlayingDude]

NYKid, here is my thread from last year about the iron stains: Vitamin C Tablets with zinc ... There are some links to interesting articles involving both zinc and the effects of vitamin C on your chlorine level.

 

[nykid]

Thanks, everyone for the advise! A follow-up with a post pic.

Replaced skimmer and replaced about 40% water through my water softener faucet. AA treatment at 2FC, 3lbs AA, Jack's Pink, and CUlator in the skimmer, for 12k pool. Pools stains are 95% gone after 12 hours. May get brighter over next 12 hours. I may do one more 1lb of AA or maybe throw it into a sock and rub over the deep end.

I still have some super fine dirt in the pool, Vacuumed and picked up most. Dealing with that now.

updated pic for side by side. vitamin C, who knew? TFP did!

 

[Texas Splash]

Looking really nice!