Plant substrate to be added in an already setup tank?

[theotheragentm]

Is there any kind of substrate for plants that can be added to a tank that is already running? I'd like to use some kind of substrate with nutrients in it already, but my tank is going with plain sand substrate right now. I know some of them have ammonia in them, and others are just going to make a cloudy mess. I know I can work on half the tank at a time, and maybe I can put the soil down in a sealed container and open it underwater so it doesn't foul up the water too badly.

Any suggestions/inputs?

 

[LemurLad]

Are the plants in there yet? If yes, you'll probably want to pull them up while you add the substrate. I've added Flourite to tanks before, it doesn't cloud badly if you give it a good rinse, same can be said for Eco-Complete. It could cause your tank to do a mini-cycle, depending on how much of the substrate you're planning to add. CaribSea's Instant Aquarium can be messy, but it's cheaper than the other two.
Opening up a container underwater would definitely help with clouding issues.

Edit: (Woo! 100 posts)

 

[theotheragentm]

Yeah, plants are in the tank. I figure I'd do it like this.

1. Pull out half the water in the tank while doing a gravel vac.
2. Pull the plants.
3. Push the sand aside.
4. Lay down the plant substrate.
5. Replant.
6. Cover up the substrate with some sand.

I'd probably be looking at 2/3 of the tank, and if I did 1/3 on different weeks I wouldn't run into too many issues with causing a mini cycle.

 

[LemurLad]

Sounds like a plan to me! Spreading it to a couple weeks would save you from a mini-cycle.

 

[fort384]

I can tell you from experience that ADA aquasoil gives off a large amount of ammonia. It is good substrate once it is settled in, but I would avoid adding it to an established tank (if it was on your list of choices).