I think I might have anaerobic soil. All my plants are getting squishy and rotting away, and my water is all cloudy. I have three MTS in the tank, so I didn't bother to poke the soil. What do I do? Do I have to remove the dirt and start fresh?
Poke the soil with a chopstick or knife. If bubbles come out of it, you have a buildup of toxic gas. I don't normally associate cloudy water with anaerobic bacteria, it's usually just the bubbly substrate that confirms their presence.
Do NOT poke all over! The gas in those bubbles is VERY toxic and diffuses into the water quickly. It can kill fish in a matter of hours.
I would remove the fish, invertebrates, etc you have into a clean tub of water, drain the tank, and remove the dirt. You don't have a balance at the moment, and at this point you can't really fix it without tearing the tank apart and starting over. If you want to use dirt, you should mineralize it before use. I also suggest mixing it half and half with sand, clay chips, and fine gravel before you cap it to reduce the chance of anaerobic pockets forming.
If you have a betta in that tank you need to remove it asap. The scum forming on the surface will coat the betta's labyrinth organ and possibly kill it.
I've moved my fish etc. into the hospital tank with clean water. I'm so glad I saw your post before I went and did something stupid. I'm in the process of cleaning out the planted tank. I'm very discouraged over this, but I'd like to give it another go. How do I mineralize the soil?
For now, you can poke the soil up as much as possible and then change the water completely, but you'll build up the gas pockets again fiarly quickly so your best bet is to restart the substrate. Just be sure to keep your filter running on the tank with your fish in it so you don't have to re-cycle.
Sorry, links to other goes are not allowed.
Usually, yes. The base idea behind mineralized soil is that it mimics the processes found in nature, thus eliminating the need for water column dosing. A properly mineralized soil tank setup will have it's own carbon, iron, and sulfur cycle. Anaerobic bacteria are necessary for a healthy tank, and they are natural, but not in the numbers or concentration that causes the bubbles to form.
If the post above is too hard to follow, you can basically just use pure humus, which is available by the bag for pretty cheap. To set up a true NPT that actually mimics natural biological processes you need to use other elements than only dirt, since just the dirt alone won't be able to provide the cycles needed and usually hosts too much bacteria and compacts too easily. If dirt must be used it should really be a low nutrient, or a high nutrient (of the proper proportions) mixed with clays or inert substrates.
Alternatively you can place dirt in a bucket or several buckets of water (for larger amounts of dirt) and frequently stir up the dirt. Twice a week dump out the buckets (but retain the dirt) and refill it. Continue for a minimum of 5 weeks. It will speed up a little if there is some water current so adding an airstone to the bucket will help a lot. You'll get compaction and anaerobic bacteria even after doing this, but the number will be reduced. Adding sand to the bucket will help host bacteria that break down the soil further to lessen the buildup of anaerobic bacteria. After you add the soil to the tank, add MTS right away so they can begin burrowing. You'll want at least one or two per gallon of tank in order to keep the substrate aerated enough.
This is a simplified method and it does work in most cases, the things you really cannot skip on is adding the snails right away in decent numbers. Adding too few snails will allow some parts of the soil to compact quickly leading to the pockets of bacteria.