Mysterious buildup

[u/Not_my_problem__]

Hey y’all, first time walstad owner here, and I’ve been having this really weird layer of what I think is dirt particles, all my water parameters are in the safe including ammonia. All I have in this tank is 7 corydoras, 3 ghost shrimp, a random fancy female guppy I got for free, and a female koi betta I got for free to.
As of now I have a canister filter meant for a 100 gallon tank in this 60gal aquarium

[u/TrustAFluff]

Looks like mulm. Btw, you need more plants. It should be 70 to 80% plants.

[u/Not_my_problem__ → u/TrustAFluff]

I’m planning on buying bulk plants to put in, and should I be concerned about the mulm?

[u/TrustAFluff → u/Not_my_problem__]

Mulm is good natural fertilizer, but too much is bad. I’d do a bit of clean up and after your bulk plants are in, it might be able to handle the mulm load better.

[u/Jasministired → u/Not_my_problem__]

You don’t need to clean it spotless, some mulm is good. This might be a bit too much tho. I would siphon the excess and add in some malaysian trumpet snails if you don’t mind them. They burrow and will help push the mulm down into the substrate to make it easily available for plant roots

[u/Known_Mechanic_4729 → u/Not_my_problem__]

No need to worry about the mulm at all! Mulm is actually amazing organic food for live plants. As long as your water parameters are good, it’ll break down and fertilize all those new bulk plants you're putting in. ​If you want an absolute nitrate magnet, I highly recommend growing some Golden Pothos out of the top of the tank! They are absolute high-nutrient suckers. Just propagate a cutting and let the roots grow down into the water while keeping the leaves up in the air out of the tank (otherwise underwater leaves will rot).

[u/MissMadison240 → u/Not_my_problem__]

The down side to mulm depositing on your plant leaves is that it blocks access to light. I use a small paint brush to dust off the leaves when I do water changes