Is this a Bacteria Bloom in my Substrate?

[MaryJane]

I have a 75 gallon tank with an exo terra topper and 2.5 gal water pools. I moved a few months back so when setting up the tank I used 5 bags of sand from Lowes and 3 bricks of eco earth mixed together for their substrate.
I’ve noticed this green stuff growing in the substrate on one side of the tank. Is this a bacterial bloom? Do I need to tear down the tank and put in new substrate?

[curlysister]

No, that's just some algae growing along the side where it gets light.
It should be self limiting. You shouldn't have to worry about it, it won't harm the crabs. I have a bit growing along the front of my tank right now for the first time in almost 12 years of having them!

[MaryJane]

No, that's just some algae growing along the side where it gets light.
It should be self limiting. You shouldn't have to worry about it, it won't harm the crabs. I have a bit growing along the front of my tank right now for the first time in almost 12 years of having them!

That’s a relief! The side it’s growing on is the closest side of the tank to a window so that makes sense. If it starts spreading is there something I should do?

[wodesorel]

Its completely harmless to the crabs no matter how much is there, and it can only grow as far as the light can penetrate so it can't get any further into the substrate.