JohnT said:
Welcome to TFP.
Shutting the pump off and laying it on the stain would be my first try.
I'd think an organic stain would have faded by now though.
Long
but can serve as my "kind-of" introduction.
Thanks. I can't lay it on the stain because it is on the side wall, deep, diving end, that curves from wall to bottom. That's why I'm looking for something to attach the puck to to get it down there and held for a few minutes.
As to whether it is organic or not you might be right but I do want to at least test.
I'm in searingly hot Texas and one of the few people I know who doesn't have any algae problems or need to do anything extra to keep a state of "no algae". That is except when the pool is left sitting over winter with a foot of leaves and other Crud. That's another story; our 07-08 frog pond and reason for last years (Sept 08) acid wash.
I'm a hold over to using ionization, which I've been using since the Nature 2 came out (moved here 23 years ago pool about 5 yrs old at the time) but I switched to Floatron two summers ago. I do all maintenance and most repairs myself. Had pool re plastered in 96. We started with Chlorine feeder which was already installed and no Polaris (but installed working booster pump). Couldn't use the first Polaris because the acorns from oaks were too large for opening. As soon as the, I think 280, came out we purchased one and we've never considered anything else. Of course I've replaced a few because my GIANT dogs do like to "rescue" Polaris and then "kill" it. Second summer here one of my show/working dogs (family pets 1st and foremost) (Mastiffs and Rotties), and rated nationally in top 10 of his breed, tore a cruciate ligament. Swimming was his rehab. And boy was he then hooked on swimming. His son, Mastiff, did water rescue. That lead to most others becoming "water dogs". Over a not too lengthy period their coats started bleaching out so we switched to bromine which helped considerably with the coat bleaching. BTW.... Bromine, using feeder, initially cost more for purchase, but ended up costing less as it lasted longer than chlorine.
Keeping numbers in line was not a "nightmare" by any means but required more time/energy than I had as I was on the road 3-4 days a week about half the year with the dogs, no one else at home had any interest in helping me with the pool, AND there were no wonderful sources for information, as we now have, like this great forum. Yellow algae was to be expected every summer and fall. Stores do tons of business around these parts for algaecides, almost year round.
When I switched to Nature 2, commercial size canister, no puck float, and once or twice a week chlorine shock, water numbers leveled out, no algae (with exceptions like above) and no need for constant monitoring or adjusting of anything. AND the fawn (blond) colored dogs swimming daily, some napping on steps in water, had no greening of coats. I'm natural light blond and I've never had any greening. We didn't ever get any metal stains on surfaces either. Our city tap water is moderately hard but in past 7 years or so the calcium content has lessened. Back then kept pool open year round for dogs, pump running virtually 24/7 with sweep, then Polaris running 12+ hours a day. I'll have to add here that running the pump/filter seemed to be needed to keep water clean, clear and algae free. I lost a few Nature 2 canisters due to freezing.
Did I mention that besides the dogs we live in heavy woods, with EXTREME sand and silt, frequent high winds, with dogs not only stirring it up as they play/exercise in yard but dragging it into the pool on entry. No cover.
I tried the Nature 2 express for one summer but it was not up to doing what the larger commercial cartridge could do and I did have to fight algae that summer.
So now, for my third summer, I have been using the Floatron, with floater with chlorine pucks, and addition of liquid bleach every other, or sometimes every night after the new "swim team" (two 10 mo old Labradoodles and 7 mo old Mastiff) has finished their daily, 2 hour, pool play session. The main job is clearing out the sand and much silt nightly. Polaris, with silt bags, a couple of changes a night with fresh silt bag before going to bed, and Pool Blaster for shallow end, with pump and Polaris running all night pretty much gets surfaces and water sparkling.
The staining that I mentioned did not appear the rest of last year after acid washing, using the Floatron. In late Nov when main amount of leaves came off trees, and what seems like most ending in pool I wasn't up physically to putting the leaf netting on and concrete barriers around pool. So I just basically closed the pool, drained a equipment, which is 9ft below top of pool, and set about going to therapy 3 times a week for shoulder. Floatron was not left in pool.
Spring 09, early April, I dragged all the leaves/debris out of pool, several major shockings, brushings, vacuumings, and that's when I noticed the black staining on wall at deep end of pool. Scrubbing with ss brush does nothing, neither does the little gritty scrubber that does remove the stains from the "fake" pears that fall off of the Aristocrat Bradford Pear Tree.
Every since I've used the Floatron the test kit for ions shows very little amounts of ions. I do backwash 3-4 times a month and have to add water every other day due to evaporation.
I suppose over the winter there could have been staining from the left over ions from Floatron maybe reacting with other things. I can't remember now but there were probably some small metal things in the pool over the winter that I pulled out with all the other gunk this spring.
Spending lots of time on this forum
has put some questions in my mind about continuing the use of Floatron but, gosh, things have been great for years. I do have chlorine sensitivity and absolutely cannot use it in separate spa without rashes. For Spa we use ozonator, nature 2 stick, and non chlorine shock and enzymes. I let puppies in spa a few times but won't do it again. As is I change the filter out, have several, every 3-5 days. I took a picture of a new, clean filter, the day after the doggies got in spa for first time. Incredibly dirty and hairy. Impressed me enough to take a picture.
So I guess my main question is how do I go about removing the staining if it is not organic? I don't keep enough chlorine levels in pool except for a few hours after near nightly addition of liquid chlorine (laundry type, non scented).
Pool is inground, plaster, 30K-35K with 1.5 HP pump, 36 sq ft DE filter, running 15-20 hours daily. Backwash almost weekly.
The staining is not bad enough that I would want to totally clear out the ions. I've used ionization for about 10 years and never had staining like this. Is there any way to get rid of it without upsetting my current sanitation regime?
PH - 7.5 (pretty much constant)
TA - 60 (maybe a little low?)
TH - 240
CA (approx) 180 (maybe a little low?)
CYA - 0
Chlorine - NA
Thanks, geekgranny
I tell people you not only have to be crazy to do it in 90-105 temps but getting tipsy is a good way to blur the "pain". (and make it a little more fun when doing it with a friend - my te-nite-sy, iti-bitty (girl) friend, almost 50 yr old, who drives a bus, of all things. We actually used straight acid in some places to get stains out. This is the thrid time I've acid washed since new plaster in 96 and I don't know if I or the pool can handle it any more.
I'm going to switch to BBB. 
I'M NOW READY TO START BBB 
