There's no need to layer substrates. Using Black Diamond on top of anything else will result in the Black Diamond eventually settling to the bottom. If you're using an inert substrate, my advise is to pick one and stick with it.
If your substrate is inert - sand, Flourite, gravel, Black Diamond - you'll need to use root tabs and/or dose ferts.
If you go with something like ADA Aquasoil, you won't need root tabs. Depending upon your plants and specific tank, you may not have to dose any ferts for quite some time.
You can use egg grate, sure. Make sure the wood is water logged or it won't sink. If it's not water logged, you'll want to attach it to a piece of slate or something to keep it weighted down. Hot glue isn't great for aquarium use. Stick with super glue gel and the like.
Black Diamond is coal slag, not nickel slag. Most of us use the 20-40 grade.
Substrate questions and suggestions, please?
I've been lurking and reading, like most people should do before posting a thread, though I am still at a loss. As in gardening outdoors, your garden soil is the foundation for a good crop, shouldn't it be the same for a planted aquarium?
I was reading through the FAQ and I still have some questions about substrate, so I decided to go ahead and post. Thank you all for your help and I'm terribly sorry for my ignorance.
I have a 75g drilled aquarium and I was reading about Black Diamond Blasting Grit. I went to my local tractor supply and picked up a medium grit (#30, for those interested.) I got it home and proceeded to "test" it. It seems like a fairly decent material. Does anyone recommend to use this as a base substrate?
I was considering "layering" substrates, like I have seen on here. I have some extra pea gravel that I could put on bottom, then layer it with laterite(?) and then put the Black Diamond Blasting Grit on top. Or should the grit be topped with flourite? You see, now I am confused. lol.
I was considering also using some local pieces of driftwood (washed, rinsed, cycled, etc.) and drilling holes in the ends to attach to a piece of eggcrate on bottom. (does anyone recommend ever using hot glue as a binding material?) I'm pretty sure with black diamond, you can't slope the material as well as you could others (Amazonia, I guess...) but I'm ok with that.
I'm a total newbie with this and would like some recommendations, please. I just bought 150lbs of Black Diamond abrasive to use in the tank. (I am currently searching to make sure it is coal slag, not nickel slag, which, by the way, I should get some serious help with.)
Thanks in advance.