ADA Aquasoil replacement substrate questions

[fredyk]

i am planning to put Aquasoil Malaya in a 30 gallon.

The plan is take out 75% of the water and scoop out the Profile substrate, leave the mulm. Add the aquasoil, fill, add lots of plants to absorb the amonia, thinking that will be enough to cycle. Add no fish at present.

will this work? will the beneficial bacteria be killed by amonia spikes? Do I have to do water changes, or will the plants absorb the amonia?

[krisw]

Generally, when I've switched out substrate, I just fill a 5G bucket with water from the tank before I do anything. Then, I put all of plants from the tank, in that bucket. After completely draining, and wiping down the tank, I set it back up anew with the new substrate. I figure that between the water that I add back into the tank from the 5G bucket, the bacteria present on the plants, and the biological filtering the plants do themselves, I don't even check the ammonia levels. With ADA substrates, the only thing to worry about is the pH crash (which sometimes I get, sometimes I don't), but if you're not adding fish in anyways, that's not a huge issue for you. Just don't let the pH go much below 5, or your plants might melt.

[Ghazanfar Ghori]

I agree with Kris. Empty the tank out completely before laying down the
new substrate.