Did you ever find the paper work that states what kind of finish you have? Maybe the PB can offer some assistance. I figured for sure somebody here would have some answers for you.
black \ green \ brown dots in the pool
- Thread starter LeeM2
- Start date
I found some paperwork, but not sure how accurate it is.
The quote document
six steel reinforcing rods per perimeter foot in bod beam
Shotcret/guinite structure, engineered for frost and fill conditions
white marblite plaster finish
some pool care company
Pool type - guinite - 3M Quart
3M colorguartz Ceramic-Coated Crystals brochure
it looks like the paint is "standard level blue"
The quote document
six steel reinforcing rods per perimeter foot in bod beam
Shotcret/guinite structure, engineered for frost and fill conditions
white marblite plaster finish
some pool care company
Pool type - guinite - 3M Quart
3M colorguartz Ceramic-Coated Crystals brochure
it looks like the paint is "standard level blue"
I'm getting more of these dots daily and some new ones are a little bigger (probably upto 2.5mm). Now I can see them on the bottom of the pool.
For the last couple of weeks I've been using "ultra" bleach from Aldi (6%. exp 10/10) and Austin's liquid chlorine from BJ's (12.5%. no exp date found). I have not been adding any other chemicals to my pool the last 2 weeks. Prior to that I used to shock with calcium based shock weekly with 2lb of shock (as I was told by the store), then with 1.5lb of shock (according to dosage listed on the container) and then every 10 days reducing the shock to 1-1.5lb,... and always had 3-6 tablets in dispenser, which kept my chlorine at 2-4ppm. I started noticing these dots when I started shocking every 10 days (instead of weekly), but it doesn't mean I didn't have thee dots when I was shocking weekly, I just started noticing them. I don't have any trees near the pool and I have not been brushing my pool weekly as I should have. I only brushed it when it had algae, at the end of may or so.
My CYA 30 (60 according to leslies)
FC 4.5-7 (at the end of the day I have about 4.5 and I add liquid chlorine to about 7).
CC .5
I don't have the rest of the tests handy, but I can list them here if they are important. According to leslies I don't have metals (or if I do, it's 1/2 of what's allowed, dont remember the actual number)
It seems like they have green and\or brown heads at first, but then when I brush the heads off with SS brush I have a black or dark brown spot left. It's hard to say if they are green or brown, it's more like a mix of both colors.
I think (and I hope) frustratedpoolmomis right and it is organic.
if it is organic, what should I do?
Should I try shocking the pool and if so, should I shock it with bleach to the shock level or should I go above the shock level or use something else instead of bleach?
Should I try rubbing with 3" chlorine tab? If so, can someone provide the steps so that I do it right. I used to rub a small piece of chlorine tablet against the dots for a few minutes but that worked on some black ones, but never worked on others, including the black ones that I have now.
Please advise.
For the last couple of weeks I've been using "ultra" bleach from Aldi (6%. exp 10/10) and Austin's liquid chlorine from BJ's (12.5%. no exp date found). I have not been adding any other chemicals to my pool the last 2 weeks. Prior to that I used to shock with calcium based shock weekly with 2lb of shock (as I was told by the store), then with 1.5lb of shock (according to dosage listed on the container) and then every 10 days reducing the shock to 1-1.5lb,... and always had 3-6 tablets in dispenser, which kept my chlorine at 2-4ppm. I started noticing these dots when I started shocking every 10 days (instead of weekly), but it doesn't mean I didn't have thee dots when I was shocking weekly, I just started noticing them. I don't have any trees near the pool and I have not been brushing my pool weekly as I should have. I only brushed it when it had algae, at the end of may or so.
My CYA 30 (60 according to leslies)
FC 4.5-7 (at the end of the day I have about 4.5 and I add liquid chlorine to about 7).
CC .5
I don't have the rest of the tests handy, but I can list them here if they are important. According to leslies I don't have metals (or if I do, it's 1/2 of what's allowed, dont remember the actual number)
It seems like they have green and\or brown heads at first, but then when I brush the heads off with SS brush I have a black or dark brown spot left. It's hard to say if they are green or brown, it's more like a mix of both colors.
I think (and I hope) frustratedpoolmomis right and it is organic.
if it is organic, what should I do?
Should I try shocking the pool and if so, should I shock it with bleach to the shock level or should I go above the shock level or use something else instead of bleach?
Should I try rubbing with 3" chlorine tab? If so, can someone provide the steps so that I do it right. I used to rub a small piece of chlorine tablet against the dots for a few minutes but that worked on some black ones, but never worked on others, including the black ones that I have now.
Please advise.
I thought I had read in your post that you have allready tried shocking with no change to the dots. Here is how TFP recomends to shock, it's found in pool school. pool-school/shocking_your_pool
It sounds like your CYA may be higher than what is being reported by Leslies which is going to raise your shock and daily chlorine targets.
It sounds like your CYA may be higher than what is being reported by Leslies which is going to raise your shock and daily chlorine targets.
If it's black algae, you need to shock as Shane suggested, and brush daily with a steel-bristled brush.
I shocked it with liquid chlorine 12.5% about 10 days ago and it didn't help. That's why I wonder if I should try shocking it with something else or go above recommended FC shock levels.
My CYA is ~ 30-35 according to my tests and 60 according to Leslie's tests. If it is higher then 60, then I'd say something is way wrong with my test kit or I've been testing it wrong.
I have cc of .5 and my 24hr FC loss is about 2.5ppm. So, I'm pretty sure my overnight loss is not more then 1ppm (and it wasn't when I tested)
P.S. I just ordered R-7065 to validate my CYA testing.
My CYA is ~ 30-35 according to my tests and 60 according to Leslie's tests. If it is higher then 60, then I'd say something is way wrong with my test kit or I've been testing it wrong.
I have cc of .5 and my 24hr FC loss is about 2.5ppm. So, I'm pretty sure my overnight loss is not more then 1ppm (and it wasn't when I tested)
P.S. I just ordered R-7065 to validate my CYA testing.
How long are you keeping the water at shock level? From what I've learned on this site it can take several days or more to properly shock. Especialy for the harder to kill species. Can you slice one of the bigger ones off with a razor and bring it to the surface to examine it and maybe post some pics? Liquid chlorine is your best bet for shocking as it doesnt add any other chemicals. I've never used algaecide but that may be something to consider.
Shane makes a really good point. If you can remove some material from the spots with a razor or fingernail, you can smear it on a piece of white paper, and greenish = algae and brown = iron.
LeeM2 said:
I'm pretty sure I read that some forms of algae consume less chlorine because of the protective outer shell. It would suck to spend a bunch of money on the shock process and not get any results. If it were me I would try to put the puck directly on the spots again just to make sure.
Heres another link that you may find helpfull.
pool-school/defeating_algae