It's not algae after all........help!

JamesW

TFP Expert
Mar 2, 2011
21,115
Yellow stains are probably iron. Try ascorbic acid.

I don't know where sand is coming from.

If you have dust that's brown to yellow, it's probably mustard algae. Do a full SLAM.

Do you have a good, close up picture of the sand?
 

JamesW

TFP Expert
Mar 2, 2011
21,115
That looks like filter sand. What filter do you have?

Do you have a picture of the system?

Do you have a better resolution picture of the sand?
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
34,436
Sebring, Florida
So sand is not coming in from your filter (obviously) and sand that course doesn't blow up over the edge of your pool so it's not coming from the surface. The only thing that's left is it's working it's way up into your pool from underneath......which indicates a tear in the liner.........that's about the only avenue left.

You are there and we are not so I would encourage you to re-examine your liner and find that tear. Unless you have sand ghosts and sand goblins, I can't see it coming from anywhere else.

Secondly, I believe you have an algae problem as well. Can you post a full set of test results and we'll help you with that.
 

kabs996

Well-known member
Jun 3, 2016
137
Enfield, CT
So sand is not coming in from your filter (obviously) and sand that course doesn't blow up over the edge of your pool so it's not coming from the surface. The only thing that's left is it's working it's way up into your pool from underneath......which indicates a tear in the liner.........that's about the only avenue left.

You are there and we are not so I would encourage you to re-examine your liner and find that tear. Unless you have sand ghosts and sand goblins, I can't see it coming from anywhere else.

Secondly, I believe you have an algae problem as well. Can you post a full set of test results and we'll help you with that.
We have figured we have a tear but we just cannot find it. MY husband swam with goggles three days straight and even tried using a tamper type tool to tap the liner floor to see if we can create sand coming in and nothing. So weird. It's a mystery. I dumped 3 gallons of liquid shock into the pool last night out of frustration hoping to kill any living algae. I hate closing it with a tear because I know I will lose a lot of water of the winter.
 

Demegrad9

Well-known member
May 27, 2017
362
Coventry, CT
This is definitely a frustrating case. You must have a winter cover, is it solid? If so, could you put it on for a couple days. If you are still getting sand in the pool with the cover on, then that eliminates the (low) possibility that this is something being blown in by the wind.
 

Fuldo

Silver Supporter
Nov 23, 2017
227
Port Orange, FL
You mentioned that you have concrete inside PVC under the stairs to hold them down. I'm wondering if the concrete could be dissolving from the ends and dropping the aggregate onto the pool bottom. Does the concrete within the tubes look similar to the sand found on the bottom? Is the concrete in the tubes a "home mix" and if so was the same material that's under the pool floor used for aggregate? Maybe you could remove the stairs for multiple days and see if the deposits stop.
 

kabs996

Well-known member
Jun 3, 2016
137
Enfield, CT
You mentioned that you have concrete inside PVC under the stairs to hold them down. I'm wondering if the concrete could be dissolving from the ends and dropping the aggregate onto the pool bottom. Does the concrete within the tubes look similar to the sand found on the bottom? Is the concrete in the tubes a "home mix" and if so was the same material that's under the pool floor used for aggregate? Maybe you could remove the stairs for multiple days and see if the deposits stop.
NO it is solid concrete mix bought at a home store. It's gray.