To those who do dirted tanks...

[Scapexghost]

Do you do anything to prepare the dirt? For example, sift it, or mix in sand or clay?

Im doing a dirted tank rn and tannins are a bit of an issue, im wondering if sifting out the wood chips wouldve prevented this.

[AllFishNoBrakes]

@Scapexghost I have a 6 gallon Walstad cube. I used organic potting soil, Miracle Grow if I remember correctly, and I sifted the dirt. 
 

Made a nice little gravel edging around all sides of the tank as I was hoping I wouldn’t see the dirt, dirt went in on the rest of the open space, and then I capped with ~2” of gravel. 
 

I filled and emptied the tank probably 5 times before I moved the tank to its final resting spot, and filled again for a final time. Definitely got some dirt particles in the water column each time I did this, so I netted those out, and would refill again. 
 

Once in its final resting spot I planted the bad boy and have let it just do its thing ever since. The tank is about a year old at this point. 

[JettsPapa]

I start my standard 20 gallon tank with 1" of dry cow manure, then 1" of potting soil, and topped off with 2" of pool filter sand.  I didn't do anything to prepare the bottom two layers.

[Luciferkrist]

Depending on what kind of potting soil you went with, there can be a significant amount of wood in it and WILL turn your water brown for a very long time. All that you can do is either regular water changes, carbon in your filters, redo your substrate, or embrace the blackwater. People pay good money to have good natural tannins some times.

Even if you DO want the dark water, I would always recommend sifting the soil anyway, if nothing else to make sure you keep a consistent size and texture to your base. Some soils also have things that are akin to sticks instead of wood ships, and will just create air pockets that you don't want.

If using an enriched soil, you are probably going to have significant algae growth while cycling, even if you heavily plant it when starting, and will have a longer cycle since the ammonia will be already present from the soil.

[FlyingFishKeeper]

Hi, at least for me and my tanks with Miracle-Gro potting soil I just dump a thin layer in the bottom of my tank then put substrate on top. So far no tannins since it was set up (around the end of 2020) but like the post above me says, you can do a fee things to remove them, if needed. Hope this helps!