Hi, Iām constructing a planted tank with some fishes however Iām a bit stuck on which soil I should use, I saw tropica soil for Ā£37 for 7kg which is too expensive seeing as Iād need around 15-20kg. I want to use it because Iāve heard that the soil reabsorbs nutrients from the water so you donāt need to replace it for a very long time. Also do I need anything else like a concentrate?Thanks.