50 Gallon Tank Capping ADA aquasoil with sand to save money?

sometime in november, i will be setting up a 48 gallon aquarium as an upgrade for the fish in my 9.5 gallon tank.

i did a fish in cycle using ADA amazonia aquasoil ver. 2 by performing 50% waterchanges everyday for about a week and a half while also having used cycled media from my 6 gallon tank. i also dosed prime each time to protect the fish from any ammonia buildup overnight.

the cycle completed successfully without any fish being harmed, however now i am wanting to upgrade them to a much larger tank.

i want to use the ADA amazonia aquasoil again in the tank, however for the size of this aquarium (45cm height x 122cm width x 36cm depth) it is going to add up by quite a lot in price. i was instead thinking of just putting around 2 inches or so of the soil at the back and then filling in the rest with a black sand. would this work out? i don't grow plants in the front of the tank (other than some anubias attached to rocks) so having aquasoil there isn't overly necessary. i always fill in the back of my aquariums with lots of stem plants and then for the midground some java ferns and maybe i'll try out crypts in this tank.

i usually only have about maybe 2 or 3 inches of aquasoil sloped up at the back of my tanks anyway, and this seems to be enough for the stem plants that i'm growing.

i just thought i would get some opinions on this. it's a couple months until i get the tank anyway, and i'm just trying to get everything together before i buy it.

 

from what I read people generally cap the aquasoil and all that type of stuff to keep the debris over time down in the tank, and kind of hold the nutrients and the soil down below the sand.

I think its' pretty common practice, maybe not as a cost saving thing, but all around a water clarity thing when you have fish rooting around and it breaking down and stuff and getting kicked up into the water. the sand cap kind of holds it all down and in place.

 

You will be fine doing this. I've capped aquasoil when I've used it in low tech setups because I don't want as many nutrients as the plants won't be able to make use of them without co2 and high light, making algae more likely

 

Absolutely fine, many plants grow well in just sand anyway. When we made the 160 x 60 x 60 tank I bought just 5kg of aqua soil, putting most of it in places where I was going to plant Amazon swords etc. The rest was river sand. I am sure the aqua soil must have lost all its nutrients by now but the plants are still doing well with only occasional liquid fertilizer.

 

I do a layering system. regular rocks/gravel as a bottom layer to add height, mesh bags of aquasoil (or loose soil) on top of that where I'll want to put plants in, then cap it all off with sand. keeps everything together and I can add more/less gravel for more or less height. I usually put it in the back of the tank so I have a slope leading down to the front. sprinkle some root tabs in the aquasoil layer and once it's capped you can easily add tabs with tweezers and push them down. My plants do fine that way and gravel is cheaper than buying a lot of aquasoil when i just want height