[cwb141]

I'm planning on starting a new planted tank by January and redoing a current one and had a couple questions about putting together a substrate.

Tanks are 20 gallon long and 29 gallon. One will be low light (35W fluorescents) and the other high light (65W + 65W for 4hrs PCFs). Eheim classic filters and CO2 injection). Tetras, dwarf cichlids, and kuhlis will be fish species. Maybe a rainbow shark in the 29 gallon.

Now, my questions have to do with how to fertilize the substrate. I have a 5 gallon bucket of aquariumplants.com substrate as the main gravel (inert? probably). I also have earthworm castings that I am going to mix in beneath the top layer.

1. According to Steve, http://home.infinet.net/teban/substrat.htm, there are 6 macro-nutrients used in large amounts, nitrogen (N), phosphorus (P), sulfur (S), calcium (Ca), magnesium (Mg) and potassium (K). What will the earthworm castings contribute as far as these go?
2. How do you add other dry ferts to the substrate? If I ordered from aquariumfertilizer.com would I be able to add the ferts to substrate by mixing with clay and then into bottom/middle substrate levels?
3. From what I've gathered I could do the gravel, ewc, and some dry ferts mixed in clay such as potassium sulfate, dolomite, a phosphate, and maybe a trace mix. Would this be okay?
   

Thanks,

cwb141

 

[Chuukus]

You should not need to add dry ferts to your substrate. Earthworm casting will grow plants fine. Save the dry ferts and dose EI style.

I have tried lots of DIY substrates some with sucsess and some without. I want to share with you what has worked best for me. I use a mixture of laterite e.w. castings mineralized soil vermiculite and fritted trace elements.

If I were you I would mix EW castings with some of your A.P. substrate about 50 50 put about an inch of this on the bottom of the tank you can add laterite of fritted trace elements or whatever you want. then put a 2 inch cap over tp of that.