First start by cleaning out the aquarium.
Then I used a plastic tube, long enough so it that goes from one corner of bottom of the aquarium, to the far corner, and then out so you can add a spout for watering.
Drill holes in the tube at a couple inch intervals to allow water to seep out evenly.
I used a candle to fill the end as to not have water seeping out the end. In the past i used a Marette with the spring inside removed, i didn't have any lying around, so i had to make due with ingenuity.
Take some sand
And some peat
And guess what the third ingredient is?
mix it all together
I put a small layer of vermiculite in the bottom, don't know if it changes anything... Fill terra with the mix, the weight of the peat mix should hold the tube in place.
CP's not suggested for this type of terra:
D. Adelae (it just spreads too quickly from the roots)
Utrics in general (same deal) but i like the look
Sarrs : small guys are fine for a bit, but they don't look as nice as those outside in full sun.
Temperate plants (i have only had bad experiences with the following, in a terra of this type: D. rotund, D. anglica)