Substrate Layering

Planning my substrate for my new 175 (60"L x 30"Tall x 24" wide) build. I've watched dozens of videos and read lots of blogs. Wow so much conflicting info out there hard to decide. I'm going with a low tech (no Co2) tank. I want to hardscape an "S" shaped wall about mid tank and build the substrate up to 12" to 15" in the back. I'm considering going with a few bags of 1/2" lava rock from Lowes ($5.50 a bag) to get me about half the way there and the rest of the way with Carib Eco Complete. This will be a "fairly" cheap low nutrient substrate so I'll add plant tabs as needed. I don't have any experience but feel like a lot of these very expensive soils with all the nutrients, like any soil, will lose there nutrient value over time and be no better than a cheaper version and need plant tabs down the road anyhow. Not planning to plant the front half of the tank and will go with a light colored cory friendly thin layer of sand.

Would like to get some thoughts or other suggestions. Tank wont be here for 8 weeks so got plenty of time to think about it.
thx Ken

 

Look at Quikrete all purpose gravel.
Lowes & Home Depot sell Quikrete gravel in the lawn & garden dept. It's aquarium safe & very inexpensive. IMO, it would make a good sub layer.
I use it in my 120 gal. & 65 gal. Works great.

 

I like the quickrete gravel idea. I think I might mix it with the lava to fill in the voids before I put on the Carib in hopes of keeping a nice porous subbase. Might mix in a bag of ADA or some type of soil with the Carib to give it more nutrients to get started. Plus I read the the ADA soil will release some ammonia initially which might help get the tank cycled.

What type of soil did you use on top of the quickrete?

 

The fish I keep make it nearly impossible to keep a planted tank. I use the Quikrete gravel as the primary substrate.
It supports over two hundred pounds of limestone hardscape & allows digging Cichlids to make nests. The Quikrete is very versatile.

 

So crazy idea for my substrate. Still planning to to build up the bottom 3"-4" of the substrate with 1/2" lava rock and pea gravel to fill in the bigger voids so a inert lower layer with lots of porosity for bacteria. Bought some Miracle Grow Organic soil and my plan was to mix it with ECO Complete for another 4" or so and then cap with a couple of inches of straight ECO Complete.

I hear airstones are beneficial on non CO2 tanks so my crazy idea I'm thinking about is to sink two 1" clear plastic tubes to the bottom of the tank and drill lots of holes in the bottom 4" (lava rock layer) and drop in air stones kind of a make shift undergravel filter to help keep the substrate aerobic.

 

I think the airstones are a really cool idea, but I would NOT use that idea if you're going to be using Miracle Grow. The way I see that going is a horribly muddy headache. My theory is that the air would probably agitate the soil and push it up into the water column, which would create that mud I mentioned earlier. Also, the organic version of Miracle Grow isn't brown like the standard version. When the organic stuff gets wet, it is BLACK. Without the soil I think it could be really cool and keep the substrate aerobic as you said, but I see the soil creating a problem for you. If you're really sold on the idea, I would test it in a bucket first, let it run for a little bit, and see how it looks. If it works, great! If not, at least all you have to clean out is the bucket and some gravel.

Note: If you make a build thread about this, send me the link please!

 

I think the airstones are a really cool idea, but I would NOT use that idea if you're going to be using Miracle Grow. The way I see that going is a horribly muddy headache. My theory is that the air would probably agitate the soil and push it up into the water column, which would create that mud I mentioned earlier. Also, the organic version of Miracle Grow isn't brown like the standard version. When the organic stuff gets wet, it is BLACK. Without the soil I think it could be really cool and keep the substrate aerobic as you said, but I see the soil creating a problem for you. If you're really sold on the idea, I would test it in a bucket first, let it run for a little bit, and see how it looks. If it works, great! If not, at least all you have to clean out is the bucket and some gravel.

Note: If you make a build thread about this, send me the link please!

Good point. I'm thinking that the amount of "draw" created would be minimum and might not be a problem. If it is a problem I should be able to just pull out the tubes. I have a build thread started but I'm waiting for the tank probably another month. Planted Angel Tank Build | Freshwater Aquarium Builds Forum | 483007

Kind off on the fence with the whole soil idea. Just looking for a way to get some nutrients into the substrate and I think the price of some of products like ADA soil is ridiculous considering the nutrients will be used up in a couple of years anyway. Might just go ECO Complete and root tabs down the road. Seems like regardless of what kind of substrate you use you'll need to supplement in a few years anyway and I don't ever plan on replacing the substrate once it's in.