uncapped potting soil for shrimp tank

[Zante]

I'm planning a shrimp tank for crystal red shrimps, and I want it to be heavily planted.
I also want the substrate to be dark, so uncapped potting soil would be ideal in that sense.

Consider that I will be starting with a cycled filter, and that I will not be stacking it for a month at the very least.

It's very hot here and I haven't sorted out the cooling yet, but I can use this time to let the tanks settle and the plants grow out.

Talking about plants, I'm thinking of some cabomba or elodea in the background, a peace lily in a basket at the waterline and a carpeting plant.

What carpeting plant do you suggest that'll stay low, fill out nicely and not need too much CO2? Some CO2 is going in, a sugar and yeast set up with a bell chamber to dissolve the gas in the water.
The lights are 32w LED lights in the center of the tank, about 10 to 12 inches from the water, the water will be about 9 to 10 inches deep. Base of the tank is 24x12 inches

 

[Tim Harrison]

You could try it, it'll get stirred up every time you move plants or hardscape around. Best to soak it first for a couple of weeks and net anything that floats. You could also consider capping it with black sand.

 

[Zante]

I don't tend to move stuff around when I've set up a tank, and it'll be a couple of months before any stock is added.
I was just wondering what problems could uncapped potting soil cause.

Also, any suggestions for carpeting plants?

 

[zozo]

This summer i tested Pond soil for Lilies as substrate in an outdoor aquarium.. It contains 30% heavy blue clay which works in your advantage regarding consistancy. The clay has a sort of natural suction, its kinda adhesive, more compact and moldable when moist. Tho once submersed and you poke in it, it feels like a very soft slurry, but it stays surprisingly well in shape if sloped to the back. I only used it at the back corners sloped up for the bigger plants. Capped it with sand and topped the sand with gravel, so it has quite some weight on top but it still is in place the way i scaped it for the past 5 months. I guess it's due to clays adhesive propperty. And the heavier sand and gravel in the non sloped mid section prevents it from sliding. Beeing a soft slurry makes it very easy to plant, plants love it grow like weed and once the plants are well rooted it makes the soil even more stable.

Tho i wouldn't think of it using it uncapped, that is definitively going to be a slurry mess. The problems it could cause, even more if uncapped, it will leach massive amounts into the water column. That's why i'm always a bit reluctant to use this in the what i call pond with the goldfish, it can easily trigger an algae bloom, pea soup. In a tank capped with sand it rather stays where it is, down bellow at the plant roots where it needs to be. If i use it, for plants prefering, it i only use little of it bellow in the baskets and still cap it with sand and gravel. You wont need massive amounts of it, use it wisely at the section where the heavy rootfeeders are planted. The lesser demanding plants planted in sand next to it, will take up what is leached into the water column and grow.

Very good and very easy non co2 carpeting plant are Liliaeopsis brasiliensis or tad bigger Sagittaria subulata.