Spots on floor of pool. HELP!

[rev29k]

I am stuck trying to figure out what this is.
(See attached pics).

I have been reading and initially tried to isolate organic vs inorganic by first putting crushed up Vitamin C in a sock on it and letting it sit for a while with no luck. So I figured it’s organic. Went to Pool Store, and they gave me some 60% calcium hypochlorite shock, which i tried putting some directly on a stain (I’ve got a bunch of spots, some of which are on the sun shelf so easier to access). That seemed to do the trick, so I figured it was organic, bought some more shock (16000 gal pool/spa) and added both bags. The next day I checked levels were as follows:

FC 13
TC 0
TA 110
CYA 45
pH 7.8
CH 350
Salt 3300

This was started last Saturday (6 days ago), and the above levels recorded on Sunday. I checked my FC levels throughout the week and by Thursday (yesterday) it had dropped to 10. I then got another shock bag and went around the pool and poured a small mound of shock on each spot using a 3/4” pvc pipe to direct the fall. Left this to sit overnight. I went out again this am, and a lot of the mounds had not completely dissolved, some had. I brushed away the leftover mounds and a lot of the stains are still there. It’s hard to tell is any of them are gone or not, or just faded. I then used the remainder of the bag to spot treat the spots again in the same manner. Let it sit for a couple hours, swept and they are still there.

I thought maybe my pH was too high for the Chlorine to work, so I added a bunch of Acid and then ran the pump on full for a while, then took a sample to the store to get a pH reading, since I know it can be hard if FC is over 10. They said ph was 7.4.

The owner was off (who I had been dealing with, and another guy told me to try a puck. Did that, scrubbed it with one for 10-20 sec, and it didn’t seem to change from what I could tell. Perhaps it faded, but if so minimally.

So now, kinda stuck/frustrated as to what course to take next. Pool is only 6 months old.

Any ideas? Otherwise it’s back to the store to see what they think. Do I need to raise my FC levels and/or keep it elevated for longer? I’m really stumped how to proceed.

TIA folks!!

Sean

 

[kimkats]

Sorry to see this happened. The first thing you need to do is STOP going to the pool store for testing. Their results tend to be more wrong than right for many reasons. Please see about getting your own test kit. Look do at my siggy below for the test kit I think is the best bang for the buck.

Next give this a read: SLAM Process This plus brushing is what I would try to see if the continues elevated FC will help at all.

Kim

 

[rev29k]

I do my own testing. I use the Taylor K-2006 testing kit. I have tried brushing with both a regular and a fine metal brush and the spots do not brush off at all.

 

[kimkats]

I do my own testing.

AWESOME!! Now go here SLAM Process and push your FC up the SLAM level for your CYA and keep it there for at least 3 days while brushing those areas. Let us know what happens. I do have another idea but want you to do this one first.

Kim

 

[rev29k]

So I bought a test kit for metal staining, which came back negative (which I already suspected, but just did it to be certain what to rule out), so I guess we know it really is organic. And since the wife swears it’s green colored (hard to tell against the dark blue finish), I ended up getting some Super Green to treat for algae. Just put that in. Not sure if SLAM’ing after putting in the algeacide is a good idea or not.

 

[kimkats]

The SLAM could take the place of the alagecide. I will get my chemistry guy on here to see what he thinks. Can you please post the ingredients of what you put in please.

@JoyfulNoise can he push the FC up to SLAM level with that stuff in his pool?

 

[JoyfulNoise]

Is it Suncoast Super Green Algaecide?

If it is and if you added the entire bottle, then you just put 1.4ppm of Cu metal ions into your pool. That’s easily enough copper to add to your staining issues.

Following the previous advice to SLAM your pool would have helped to identify the problem. Your signature says you pool plaster had abalone shells added to it. Abalone shells, if not properly processed and rated for pool use, will often cause brown organic staining due to the proteins in the abalone shell. A SLAM would have helped to differentiate a green algae issue from an organic stain. However, with the copper on board, you are now likely to get a mix of copper metal stains (often brownish colored) as well as the organic stains.

It’s best to listen to the advice given here rather than the pool store and it’s best to ask people here before adding unknown chemicals.

So, if you want to lower the risk of copper stains, you’ll need to drain and refill about 1/2 to 2/3rds your pool volume. However, you must be careful doing so if your ground water level is high because you can pop your pool out of the ground. I would suggest doing an exchange based drain and fill where you remove water from the deep end while simultaneously filling in the shallow end. Either that or wait for some heavy rains and let rain water overflow your pool.

You’re other option is to try to SLAM the pool knowing that your plaster could be uniformly stained. Spot bleaching with cal hypo powder might work but it will be tedious as you already know.

 

[rev29k]

Yes it is Suncoast, but I only put in the directed amount (2 oz. per 5,000 gal., so 6 oz.). I too was worried about adding too much copper as I have read, but I definitely didn’t put in the whole bottle. I do know from a recent test (using those “disks” they put in a portable centrifuge) that my copper level as at .1, if that helps. But no, I only added 6 oz. to a 16,000 gal pool/spa. Also, I did notice there aren’t any spots on the spa. I’m guessing because it’s an infinity and the turnover in it is probably quicker than the rest of the pool.

So JoyfulNoise, am I OK to SLAM since adding that amount, or do I need to wait a week and then do it? I don’t plan on adding any more algae use if it doesn’t show any difference.

 

[JoyfulNoise]

Yes it is Suncoast, but I only put in the directed amount (2 oz. per 5,000 gal., so 6 oz.). I too was worried about adding too much copper as I have read, but I definitely didn’t put in the whole bottle. I do know from a recent test (using those “disks” they put in a portable centrifuge) that my copper level as at .1, if that helps. But no, I only added 6 oz. to a 16,000 gal pool/spa. Also, I did notice there aren’t any spots on the spa. I’m guessing because it’s an infinity and the turnover in it is probably quicker than the rest of the pool.

So JoyfulNoise, am I OK to SLAM since adding that amount, or do I need to wait a week and then do it? I don’t plan on adding any more algae use if it doesn’t show any difference.

The copper is in your pool water “forever” or until you exchange pool water with fresh water. You added roughly 0.25ppm copper to your water at that dose rate. That puts you roughly at 0.35ppm which is probably on the edge of staining (and, incidentally, not at all near the level needed to kill algae which is about 1.5-3.0ppm).

If you SLAM, you might develop patchy staining of the plaster OR the copper might get captured in the filter. Copper scale is usually a blue-green color. When you’re done with the SLAM, open your filter and check the cartridges for blue staining. If they are stained, soaking them in diluted MA will remove the copper.

 

[rev29k]

So I’m already at FC 14.5 as of today. And SLAM’ing could cause Copper staining? Then I’ll just have another problem I’m trying to fix. I’m not about to empty out part of the pool, that’s just silly. I’ll wait until rainy season (which means downpours every day) and just let Mother Nature do it before I drain it.

This is extremely frustrating. Or, if I SLAM it now, how hard is it to get rid of copper stains?

 

[rev29k]

So is my only recourse to dilute the pool before SLAM’ing, or else risk Cu stains? And if I get Cu stains, how hard are those to get rid of?

 

[Flying Tivo]

CYA of 45 is not measurable, only in 10 increments the scale is logarithmic. Round up to 50 and SLAM accordingly to this level of cya.

 

[rev29k]

Tivo,
If I SLAM now, do I have to worry about Copper stains?

 

[Flying Tivo]

Im not the metal expert around here, but as suggested earlier, you should at least drain and refill 1/2 of your water. I would guess water in florida is cheap.

 

[rev29k]

Not at all. And that's with a 2nd meter I had installed strictly for irrigation/hoses that I don't pay any sewage fees on. Otherwise it would be twice as much. I do think they have faded a bit since I dropped my pH after shocking it. I'm contemplating just letting it go until rainy season, letting the fresh water dilute it, and then maybe SLAM'ing then. I've never "SLAM"ed my pool (ie taken FC that high), but so far no stains from just going to FC 15.

Thoughts???

 

[Flying Tivo]

Your FC needs to be at least 20ppm