I can totally redo the tank if need be.
Well - not really. You can have a perfectly nice planted tank without it being a dirt tank (NPT) if you're prepared to feed the plants some ferts now and then. Root tabs for the root feeders (swords, crypts, lilies) and Flourish liquid for the stems. Up to you!
I just need to know what kind of dirt to get- regular potting soil like miracle grow? is there any kinds I should avoid? How deep should the soil be?
I've noticed in my local stores a few different kinds of miracle gro - some have added water retention material or ferts - you don't want those. The soil should be as free off added anything as possible, and also sifted to removed large chunks of wood and other debris. Stay away from animal dung and especially chicken manure, according to the planted tanks stuff I've been reading.
The soil should be around 1-1.5 inches. And the sand cap half of the soil height.
Also, do I need to be poking the soil to release gas?
Yup. Unless you get some Malaysian Trumpet Snails to do it for you. I used a skewer to give it a poke before water changes at set-up (when they need to be more frequent) for the first few weeks, then the snails arrived..
Photoperiod = how long are your lights on for?
The only ones with issues are the red one and the Pogostemon erectus. Not sure if its just adjusting or dying. Same thing happens with anacharis. Does wonderful in my sisters overstocked goldfish tank but in mine it just....goes all brown.
Many of the red plants require higher lighting levels than say, java fern or some of the hardier green stems. There's exceptions - but generally speaking, red = needs more light. That said, it might be adjusting. =P
In my experience, anacharis is very fickle. It's sprouting in Daughter's 8-gallon under a flourescent light. It won't grow in any of my tanks at all, and tends to die rather quickly. I gave up on it, tbh. Daughter loves it and wants more of it for her tank. Perhaps it likes flourescent light, or my tanks have too low pH for it - something to research, there...
Anyway, before you disrupt all your plants and substrate, have a think about the NPT thing. Personally speaking, I love mine, and plan to do more of them - it's a fantastic experience and they look great, the fish is doing really well in it. But then I also like the sand tanks a lot, for the fact they're much easier to rearrange while I'm still learning about plant species.