As for the water, someone else had told me if using RO water, to not dilute it more than 50% RO. The eggs and fry still needs some hardness to properly develop. And stay away from chemicals like ph down. Don't worry about the ph. Just bring hardness down, which will bring TDS down as well. And also, the blackwater does the same I believe, lowers ph. If it does, then blackwater is ok to use as a ph lowering additive. Ph down will only bounce right back up in a couple days and cause fluctuations in ph. Once I get another tank, I'll set it up as eggs only. Currently I have no available tanks, so the eggs are still with the parents. And the parents are doing an awsome job protecting them. They are on day 2. And guess what? The other planted 10G tank is laying eggs as I type this, lol. Got 2 batches of eggs now, lol. They are the ones that have been laying eggs every 7-9 days.
As for the Eco, it's pretty fine with some larger gravel. Nothing to worry about with the eggs or wigglers. Also, I don't use under-gravel filters. So there's nothing under the Eco Complete. Just plant roots, lol.
Also, what plants are you getting from fish_4_all? He's got some good plants. For my planted tank, my main plant is Wisteria, as it will suck everything out of the water, lol. You won't have any water issues with it in the tank. There's another one I got from him that's doing excellent in my 10G, and is another nutrient hog. I believe it's a hygro, just can't remember the name off the top of my head. It's great for breeder tanks, as well as egg tanks. That way if you do overfeed, which I do with fry to make sure they get plenty to eat, I have no issues, as I have the wisteria.
Also, for snails, great cleanup crew. Just don't have them with eggs or wigglers. They will eat them. If you can make sure it's snail free til they are free-swimming, then go ahead and add snails as your clean-up crew.
