Spots on Pebble Tec pool

[sjuanie]

Long story short, life has finally slowed down and I'm taking an interest in my pool care again. I got to the point where I would do a visual check, didn't work out too well . So I have these dark spots mostly on the deep end, they appeared, spread and here I am. Finally, have my water looking crystal clear, but now the spots are more visible, so it's either go green or get rid of the spots. I bought Jacks Magic and it was difficult since the spots were in the deep end. What I gathered is I need the copper and Scale stuff though the Safe shock looks like it could work too, It was hard to tell. So this morning I grabbed a chlorine tab and scrubbed a few stains, it seemed to have an effect, though it still looks like a very light stain is left on some spots, again, it was hard to tell. Tested the water after the tabs, I'm hoping it had an effect on my CYA number because it tested at 70. On 7/7/17 it was 0, I added about 5 lbs of stabilizer. On 7/9/17 it read 30, 7/14/17 it read 35. I tested again on 7/23/17 and it read 0 again? I added another 5 lbs a few days later. So today my numbers are FC=1, CC=0, PH=7.4, TA=100, CH=280, CYA=70. I'm going to add 41 oz. of liquid chlorine and later 45 oz muriatic acid. As for the spots, I want to get rid of those as best as possible, any suggestions there? Thanks for all your help here, because of this site, I have learned how to use my Talor K-2006 kit, I finally have my water crystal clear, and I actually thought it was clear before, not even close.

 

[mknauss]

Hello and Welcome to the forum!

Great you have a quality test kit and are using it.

You do know your FC is far too low for your CYA? Please see Pool School - Chlorine / CYA Chart
Keep your FC in the target range at the time you test. Add in enough chlorine each day to raise your FC to 3 ppm above your target.

Have you used products containing copper in your pool? Algaecides, tablets with the word 'Blue' in them?

Our resident expert on metal staining is Swampwoman. PM her. She is pretty busy this weekend but will get back to you.

Take care.

 

[sjuanie]

Hello and Welcome to the forum!

Great you have a quality test kit and are using it.

You do know your FC is far too low for your CYA? Please see Pool School - Chlorine / CYA Chart
Keep your FC in the target range at the time you test. Add in enough chlorine each day to raise your FC to 3 ppm above your target.

Have you used products containing copper in your pool? Algaecides, tablets with the word 'Blue' in them?

Our resident expert on metal staining is Swampwoman. PM her. She is pretty busy this weekend but will get back to you.

Take care.

I basically follow pool math, I added chlorine but only enough to get to FC 3, I didn't realize about the chart and will add more tonight, thank you. And yes, I have used Algaecides, not sure of its contents, from HTH, the color was blue, so I assume it's what your talking about. This is awesome info, learning as I go, I appreciate your response and will send a PM to Swampwoman.....thanks again!

 

[Swampwoman]

Hi SJ. Welcome.
I'm not 100% certain that your stains are metal vs. organic from your description.

So first, let's check out a few things.

1. Tonight, do an Overnight Chlorine Loss Test - follow the instructions in the link. We want to make sure your low FC hasn't given anything an opportunity to grow before we approach possible stain removal.

2. Was dosing to 70 cya an accident on your part, or do you have an SWG (salt water generator) by any chance? That's the only time we recommend cya that high, just so you know. You may want to drain a BIT of water to reduce it if possible. Eg. Maybe 2%...provided you're not on well.

3. Are you on well, has anything sat on those spots that might have corroded, and/or have your previously used any copper algaecide or products with "Blue" in the name?

4. Please post a pic of the stains...it might help.

5. After you've done the oclt, crush up some vitamin c in a weighted sock and set it on one of the stains. Report back and tell us if it cleaned the stain any better than the puck.

Sorry I took so long to check in...big family visit weekend. I'll also be heading north on Wed, but will check in before that.
Cheers to a trouble free pool.

 

[sjuanie]

Hi SJ. Welcome.
I'm not 100% certain that your stains are metal vs. organic from your description.

So first, let's check out a few things.

1. Tonight, do an Overnight Chlorine Loss Test - follow the instructions in the link. We want to make sure your low FC hasn't given anything an opportunity to grow before we approach possible stain removal.

2. Was dosing to 70 cya an accident on your part, or do you have an SWG (salt water generator) by any chance? That's the only time we recommend cya that high, just so you know. You may want to drain a BIT of water to reduce it if possible. Eg. Maybe 2%...provided you're not on well.

3. Are you on well, has anything sat on those spots that might have corroded, and/or have your previously used any copper algaecide or products with "Blue" in the name?

4. Please post a pic of the stains...it might help.

5. After you've done the oclt, crush up some vitamin c in a weighted sock and set it on one of the stains. Report back and tell us if it cleaned the stain any better than the puck.

Sorry I took so long to check in...big family visit weekend. I'll also be heading north on Wed, but will check in before that.
Cheers to a trouble free pool.

i would guess my pool will flunk the overnight test. After getting my reading of CYA=70, which was an accident, I'm learning still, it's actually down to about 60 now after my wife overfilled the pool with fresh water while I was at work. Anyway, i added chlorine to get my FC to about 5 Sunday. Tonight it's at 1, regardless, I'm picking up some liquid chlorine tomorrow and will do this test tomorrow night as well as take pictures, I got home too late tonight to do anything. I am not on a well, and I don't have a SWG. Yes I have used the blue stuff, HTH, not sure if blue was in the name but it came out blue in color. We have had metal furniture, gazebos, and last was a metal ladder that have ended up in our pool from strong winds, I have since built, not quite finished a permanent Gazebo, with a man cave enclosure on top. So I'm sure lots of different things have been in there, could be pieces of metal from the nail gun used etc. etc. I have vacuumed the pool, but anything is possible. And it seems the spots grew overnight, it seems like it. So tomorrow I'll get the FC up to at least 3, take pics, then do the overnight test. Thank you so much, I appreciate it!

 

[Swampwoman]

Good morning. I don't think I've adequately stressed the importance of the [fc/cya][/FC/cya] chart.

Don't bother doing the Overnight Chlorine Loss Test until you have a MIN. Of 5 for your cya, as the sanitation range is 5-7 ppm for cya at 60. So that means daily dosing to around 8 ppm to make sure you never drop below 5 at any time. If you want to do the oclt tonight, I guess I'd suggest dosing to at least 7 so that if you are consuming FC overnight you're less likely to drop to the level where algae can grow.

I think right now your pool needs to be properly sanitized before addressing the stain.

There would be little value in treating a stain only to end up with algae

 

[sjuanie]

Good morning. I don't think I've adequately stressed the importance of the [fc/cya][/fc/cya] chart.

Don't bother doing the Overnight Chlorine Loss Test until you have a MIN. Of 5 for your cya, as the sanitation range is 5-7 ppm for cya at 60. So that means daily dosing to around 8 ppm to make sure you never drop below 5 at any time. If you want to do the oclt tonight, I guess I'd suggest dosing to at least 7 so that if you are consuming FC overnight you're less likely to drop to the level where algae can grow.

I think right now your pool needs to be properly sanitized before addressing the stain.

There would be little value in treating a stain only to end up with algae

Ok, just got home, FC was at 3, I added approximately a gallon of liquid chlorine, I will run the pump for about 1 1/2 hours to be sure and re check FC. Here are some photos, if you need more let me know. I will post updated FC later tonight.

- - - Updated - - -

Sorry, didnt realize the pics were so big!

 

[sjuanie]

Ok, FC at 7, will check back in the morning.

 

[Swampwoman]

Good morning.
Glad you got your FC back up

So, regarding the stains, in this case to determine whether organic, iron or copper you can do the following tests -- if they're all in the deep end, for two of them, you might need to tie a sock to a pole to let them sit for a few minutes, and for the last one, if you had any dry acid, the same, or you might wish to get a spot treating tool like this one that I ultimately think you'll end up using for treatment anyway:
https://www.amazon.com/dp/B004VLB3VE/ref=asc_df_B004VLB3VE5113474/?tag=hyprod-20&creative=394997&creativeASIN=B004VLB3VE&linkCode=df0&hvadid=198069309089&hvpos=1o1&hvnetw=g&hvrand=16659885249631678125&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=9032624&hvlocphy=9017527&hvtargid=pla-319286887400

1. Puck - pucks are acidic, so your partial lightening doesn't mean for sure its organic...could be copper and scale
2. Crushed up vitamin c - works best on iron, will lift it fast...if it doesn't, its likely copper, which it might darken to black, then lighten a bit...it it doesn't remove it relatively fast, ascorbic acid is not the right treatment
3. Dry acid, or liquid muriatic acid in the tool I linked. My hunch is that your stain is from something sitting there that had been broadcast into the pool, and that this is most likely to work.

Jacks stain remover for copper would be another option.

In general, stain treatments mess with your water parameters one way or another so for "ad hoc spots" like what you have, spot treatment is a better option when it works.

Since you're not on well, and we don't yet know if its organic or metal, I'm not sure we need to talk about sequestrants...if there is a high reading (above .3 ppm) of copper in your water, you will want to use either Jacks Magic Blue for copper or Metal Magic after you release your stains.

I'm heading out of town today to a remote area, but have let other guides know I might be MIS, so if you don't pass the oclt, they wil assist you in doing a mini SLAM Process to get a good baseline to start with.

Normally, with mass staining, waterline staining, etc. we avoid slamming because it can oxidize the metals and tint the water if the metal concentration is high. But in a case like this where it looks more like contact staining, and since your FC has been subpar and you haven't yet used sequestrant, I think you're better off ensuring there's no opportunity for algae.

Be mindful of ph...with metals, its best to keep it lower, eg 7.2. Some of the acidic treatments for copper, if that's the route you go, require closer monitoring and careful, incremental adjustment upward.

Hope that helps you get a plan together

 

[sjuanie]

Ok, FC at 6 this morning, 8 hours in between test, 10PM-6AM.

 

[mknauss]

Did you test CC? Should be 0.5 or less at your AM test.

If your water is crystal clear and you are good on the CC test, then you most likely do not have an organics issue. So move on to the suggestions Swampwoman gave you on the spots.

Take care.

 

[sjuanie]

Did you test CC? Should be 0.5 or less at your AM test.

If your water is crystal clear and you are good on the CC test, then you most likely do not have an organics issue. So move on to the suggestions Swampwoman gave you on the spots.

Take care.

Water is crystal clear CC=0.5, thank you!

 

[sjuanie]

Good morning.
Glad you got your FC back up

So, regarding the stains, in this case to determine whether organic, iron or copper you can do the following tests -- if they're all in the deep end, for two of them, you might need to tie a sock to a pole to let them sit for a few minutes, and for the last one, if you had any dry acid, the same, or you might wish to get a spot treating tool like this one that I ultimately think you'll end up using for treatment anyway:
https://www.amazon.com/dp/B004VLB3V...24&hvlocphy=9017527&hvtargid=pla-319286887400

1. Puck - pucks are acidic, so your partial lightening doesn't mean for sure its organic...could be copper and scale
2. Crushed up vitamin c - works best on iron, will lift it fast...if it doesn't, its likely copper, which it might darken to black, then lighten a bit...it it doesn't remove it relatively fast, ascorbic acid is not the right treatment
3. Dry acid, or liquid muriatic acid in the tool I linked. My hunch is that your stain is from something sitting there that had been broadcast into the pool, and that this is most likely to work.

Jacks stain remover for copper would be another option.

In general, stain treatments mess with your water parameters one way or another so for "ad hoc spots" like what you have, spot treatment is a better option when it works.

Since you're not on well, and we don't yet know if its organic or metal, I'm not sure we need to talk about sequestrants...if there is a high reading (above .3 ppm) of copper in your water, you will want to use either Jacks Magic Blue for copper or Metal Magic after you release your stains.

I'm heading out of town today to a remote area, but have let other guides know I might be MIS, so if you don't pass the oclt, they wil assist you in doing a mini SLAM Process to get a good baseline to start with.

Normally, with mass staining, waterline staining, etc. we avoid slamming because it can oxidize the metals and tint the water if the metal concentration is high. But in a case like this where it looks more like contact staining, and since your FC has been subpar and you haven't yet used sequestrant, I think you're better off ensuring there's no opportunity for algae.

Be mindful of ph...with metals, its best to keep it lower, eg 7.2. Some of the acidic treatments for copper, if that's the route you go, require closer monitoring and careful, incremental adjustment upward.

Hope that helps you get a plan together

Ok, just ordered the spot remover attachment, it will get here Saturday. I'll do the Vitamin C test and dry acid test on Saturday also while keeping my FC at 7 in the meantime. Thank you so much again, this site is really awesome as well as the people here.

 

[sjuanie]

Ok, very frustrated. I dont follow directions very well, thats a male trait right, throw away the directions and go for it. I received my spot remover attatchment from Amazon. So I really dont need to be honest but I usually wear my emotions and everything else on my sleeve, sort of an open book, and I talk too much as you are finding out. So quickley realized after crushing up the vitamin C pills that they dont go in the spot remover attachment right? LOL. My wife read the directions, so did the acid test, now my pool is a sandy colored pebble tech which after awhile looked like it had a bluish hue to it, I always worried I stained it. After putting the stain remover on one of the spots, it looked liked it was leaving a orangish streak near where I place it. After about 10 minutes I got a little concerned and sure enough, the black stain did get lighter, looked like an orange hue, with the streak which was probably acid leaching out a bit. It also looked like it ate some pebbles which my wife was beside herself, so I dove in, pebbles are ok, and after further review, im thinking maybe the pool was stained and the orange color is actually the original color coming back? It looked actually sandier as I compared it to our steps which look like the original color. But not knowing for sure, I stopped the test. So after 10 minutes, the stain did lighten up, as well as the non-stained area around it. I still need to do the vitamin c test but thought I would post this first. Should I have kept the acid on there longer? I really want to tackle this myself, but is it possible it will need an acid wash down the road and what do companies usually charge for that? Thanks again for your help, I'm getting there, or am I...lol

 

[Swampwoman]

We need to compare tests to learn what affected the stain most quickly.

And yes, you can use the crushed up vitamin C in the tool if you want by just adding a bit of water to it, or tying it to a sock on the bottom of the tool for testing purposes.

 

[sjuanie]

Added vitamin c to water, poured it in the tool and it didn't seem to have any effect. At this point I'm getting frustrated. Let me retract a bit, I bought the stain kit from Jacks magic, test kit 2 seemed to work best from what I remember, but nothing obvious. I had a hard time with the kit since most stains were in the deep end. I did have a few stains on the side near a rock, I hit that with a Tricor puck, scrubbed with a brush and it cleaned up pretty well. Bought the tool attachment so I could use muriatic acid. After about 5 minutes I noticed a light stain leeching out on my pebble tec finish, got worried and lifted it out. So there is now a light stain, outside of my problem stains, which it got rid of almost all of it. The light stain the muriatic acid caused I attribute to maybe my pool was stained a light bluish green hue and now it's showing its natural light sand original color, at least that's what it looks like to me. So nothing is REALLY standing out as far as Aha, that did it. So in a desperation move, I poured liquid chlorine in my attachment thinking if the Tricor tab worked ok this may, well, it did. So seeing that I tried another spot and it seemed to not do much, maybe I'm holding the tool wrong, whatever, it's confusing and I'm ready to fill it in with dirt..JK! So in conclusion, I cant really say what works and what doesn't, Acid definitely did something, as did Tricor tab and liquid chlorine. Acid made me nervous as it left a streak on the bottom, but it may be because it cleaned it back to its original color.

 

[Swampwoman]

If you recall Jacks Stain Test #2 working, plus the fact that the stain responded to MA and lightened, that leads me to be reasonably confident you're dealing with copper. It also sounds like its possible you have light staining on your entire surface.

Jacks Stain #2 treatment is proprietary but TFPers have reason to believe it is sulfamic acid, whch is typically more effective on this kind of stain. Since you're uncomfortable using MA in the spot tool, I'm thinking you might be happier using Jacks #2 and doing the whole pool treatment with it because it should uniformly restore the original color. Just be sure to follow the directions, follow up with sequestrant, and note their warning about the product interfering with FC reading by causing high cc readings for about a month.

 

[sjuanie]

Awesome, if nothing else it's a start. My CYA is down to about 45, FC is 5, all other numbers are in range. I REALLY appreciate your help and I agree, I do believe the deep end of my pool has a very lite greenish hue to it, I think the MA restored it to its original color when I applied, I compared it to my steps in the shallow end and it looked the same color. I'll get started on it this weekend and order Jacks Stain #2 treatment. Again, thanks for taking the time to help!

 

[sjuanie]

If you recall Jacks Stain Test #2 working, plus the fact that the stain responded to MA and lightened, that leads me to be reasonably confident you're dealing with copper. It also sounds like its possible you have light staining on your entire surface.

Jacks Stain #2 treatment is proprietary but TFPers have reason to believe it is sulfamic acid, which is typically more effective on this kind of stain. Since you're uncomfortable using MA in the spot tool, I'm thinking you might be happier using Jacks #2 and doing the whole pool treatment with it because it should uniformly restore the original color. Just be sure to follow the directions, follow up with sequestrant, and note their warning about the product interfering with FC reading by causing high cc readings for about a month.

So it looks like I will need 15 Lbs since my pool is around 16,000 gal. Ouch! Which Sequestrant do you recommend?

 

[pooldv]

Proteam Metal Magic or Metal Out seem to work best.