Grey Patches In Gravel

HI all I have over night/during the day developed a problem. It's greyish patches in the pebbles are clean no slime etc the dark colour won't rub off thought maybe start bba but I don't believe so it's my quarantine tank only new addition is golden apple snail that came pre-loaded with algae
All parameters are on point same with temp. This is the closest I can get pic before goes blury crappy phone

Tia

Forgot mention I gave those spots of gravel a deep vac clean and just quick sweep over the rest it did have a strong dirty odour smelling odor as it was coming out in the bucket

Gets 50% weekly wc due to stock levels in qt

 

I can’t see it. I’m sorry.
But is it a true apple snail? A going to be softball size apple snail? You know they’re the messiest snail ever right? Where’d you get it? I know I’ve got to tell my heart no no no! But I miss my Fred and Barney!

 

Uptowards the snail the darker patches compared normal lighter gravel lower in . That I couldn't answer I'm not really up-to it with snails but it appears to be from research got it from local lfs not wrong about being messy quiet useless creature just seems to cruise around go get some.air and repeat very unusual which attracted me to him/her I will eventually rehome him/her when I can find a forever home was a silly impulse buy not keen on him leaving the the qt go to the main tank so he/she has just been chilling In there for a while now

But it's the darker spots up towards top.of photo really sorry about bad pic can get closer without it getting blurry qt has always been running g fine except one case of ich months and months back thank goodness for qt

 

Uptowards the snail the darker patches compared normal lighter gravel lower in . That I couldn't answer I'm not really up-to it with snails but it appears to be from research got it from local lfs not wrong about being messy quiet useless creature just seems to cruise around go get some.air and repeat very unusual which attracted me to him/her I will eventually rehome him/her when I can find a forever home was a silly impulse buy not keen on him leaving the the qt go to the main tank so he/she has just been chilling In there for a while now

But it's the darker spots up towards top.of photo really sorry about bad pic can get closer without it getting blurry qt has always been running g fine except one case of ich months and months back thank goodness for qt

Asked hubby to look but he can’t find it. I’m blind so I’m no help.
Hubby thinks it’s a mystery snail. Bummer. But I hope you find a good home for it.
Is the grey stuff like fluffy or flat? Has it changed at all?

 

Interesting with the snail... Hmm
It's slightly grown more not fluffy/ furry or flat it's just turned the gravel grey tried rubbed it off with my fingers it's stained ive used no meds since and before this has happened except for the one case of ich which was months prior but I did a deep gravel Clean under those grey spots water Coming out had a foul odor (like something has died) and tried deep cleaning a spot to the bottom.of the pic where the normal gravel was just had a earthy smell gave the rest a quick surface SkI'm didn't want to upset my bb to much

As it's run by aqua one 101f for filtration. Only a 20lt tank otherwise I'd be using a canister so my bb home is limited to substrate and the tiny little foam filter

Not sure what exactly what it is my Searches came back empty if it's worth while shutting the tank cleaning tank thourghly and replacing gravel and set back with recycling as I'm trying to stock my main tank might be best to wait out until I know what it is how to treat

I'm thinking maybe bacterial

 

It’s odd. I’ve never had anything that sounds like this. I’ve had nastiness from food getting down in the gravel and me missing that spot when I vacuumed for a while. But never a grey coloration that wouldn’t come off. Sorry I’m no help here.

 

All good thanks though