Brown/Black spots and brown stains

[AGT]

Hello again-

I have checked my levels with strips and showing basic normal levels except FC is low. Leslies said 1000 phosphates, slightly high PH and low FC so I dumped 8 bottles of bleach and my last lb of shock. Now FC is only 2-3ppm and stains still there. The dark brown spots are nickel to dime size and come off with a pumice scrubbing. Black algae? My other concern is those brown faded stains. They are on the walls and the floor and I thought maybe the high PH. Suggestions?

 

[AGT]

I should have searched 1st. The brown/black spots I will try to remove with the trichlor. The brown stains I am not sure of. The look like a coffee stain on the wall or floor of my plaster pool

 

[Butterfly]

Can you post a full set of test results?

Forget about the phosphates. They are a non-issue in a properly chlorinated pool.

Are the brown/black spots round? Black algae spots are round and BA usually occurs in a pool that has been 'let go' for a period of time.

A pic of the stains would be helpful.

 

[Raaron]

If you have tablets put a glove on and scrub the spots with the tablet. If the tablet gets rid of them it's probably algae.

 

[AGT]

Test results. I need to order a TF kit but for now here is what the pool people showed

FC: 1
PH: 8
TA: 110
CYA: 30
CH: 170
TDS: 500
Phosphates: 1000

 

[AGT]

Sorry if hard to see. Kreepy got the water a little wavy

 

[AGT]

If you have tablets put a glove on and scrub the spots with the tablet. If the tablet gets rid of them it's probably algae.

Tried yesterday. No go

 

[AGT]

Okay I tried vitamin C tablets and they just left a orange-brown temporary stain. I am guess its scale and needs lower ph?

 

[RobbieH]

Yes, your pH is high. It may or may not help with the stains, but needs to be brought down anyway. Plain muriatic acid from a home improvement store is all you need.

 

[AGT]

and I just add it to water from the pool in a bucket. then test after an hour?

 

[RobbieH]

Pour it directly into the pool in front of a return. Wear eye protection, try not to suck in the fumes. I do not recommend people mix acid and water before adding, because some people will do it in reverse order. Adding water to acid can be dangerous.

 

[Butterfly]

and I just add it to water from the pool in a bucket. then test after an hour?

Have you never used muriatic acid?

You should wear eye protectors, at least some sunglasses, and don't get downwind of the muriatic acid.

Wait 30 minutes between adding MA and bleach. They do not play well together.

Also, do not store the MA near chlorine products. Preferably store it outside, out of the sun. I keep mine under the deck behind a pillar - all by itself.

Never add water to acid, ALWAYS add acid to water. So, yes, you will measure the MA (preferable in a plastic container) and then slowly pour it into the pool in front of a return. Test in about an hour is fine. If any gets on your skin make sure you do a good rinsing.

If any spills on decking or anything else, give it a good rinsing, too.

I'm sure some members will chime in with their MA garb

RobbieH types fast and has great info

 

[AGT]

Thank you both. I appreciate it. I have never used Muriatic but have used chemicals and will definitely be careful. I have let my chlorine levels slide down to nothing so I should be good there. Thank you for the storage info too.

 

[RobbieH]

It is OK to add acid when your pool has chlorine. Just don't add them at the same time. Wait 30 min or so between the two.

 

[AGT]

Thanks Robbie

 

[AGT]

Okay. PH is down a little. Chlorine is back up to 2-3 and I believe the spots are fading. My wife still sees them very well tho let me tell ya. haha