new in the tenner

I found the new substrate I want to put in my aquariums. To make them proper low-tech planted, with the substrate holding nutrients for the plants. Anxious not to screw it up, so I started out by just adding some into the smaller tank, to see how it goes.

I bought this fired montmorillonite clay called safe-t-sorb. It's just over $5 for a forty-pound bag. (In comparison, a ten or eight pound bag of something made for aquariums can cost up to $16! and those don't always have nutrients in them either). The pro for STS is that it has a high capacity to suck up nutrients and hold them, plus its a clay which has some macros already- if I understand all this right. The downside is that: it's dusty. Needs to be cleaned a lot. It's lightweight, floats up easy if disturbed. It sucks carbonates out of the water and until reached capacity will lower pH. That might be good, except then the pH will be unstable every time I replace water.

So I'm just trying it out, will see how all of that goes for me. (I've read of methods to replace gradually part of the old substrate with this stuff, just handfuls at a time over the weeks until it is all STS, so that the changes are not too drastic and you don't have to pull out all the fishes. Might do that if I convert the main tank too.)

Here's how it went. First I sifted the entire 40lb bag through a window screen, removed about a fifth of the volume in dust and fine particles. Then screened just a few pounds through an old plastic collander, removing half again of smaller particles so its more even size, larger bits.

Then I tried "charging" it. It soaks up a lot of stuff immediately- that's why sold for traction, spill cleanup and the like- so you soak it in a bucket of water that's full of fertilizers, and then the clay holds them for your plants. The science on this is not precise, I read how some people did it- the important part is to keep the fert ratios the same as when you normally dose the tank. I dissolved four EI doses of dry ferts and liquid micros into a gallon of water, then soaked the STS in that. For just over an hour while I did regular tank maintenance. I think now this wasn't long enough. Most people soak it for an entire day, or a week. I'll do it longer next time. Yeah, it's really dirty.

After doing regular water change on the tank, I used the old tank water to rinse out the STS (because it's already got chlorine removed, and I usually pour ten gallons down the drain anyway- have way more than my houseplants can use each week) and then filled a five-gallon bucket with clean water, dechlorinated it, rinsed with that again. In a small plastic container. Even after the two siftings I'd done, it still took about twenty rinses before the water was relatively clear. And then when I sprinkled it into the tank, it was still cloudy for about half an hour.

I don't know if this will benefit the plants in here any. They're all epiphytes. They do have little runners that go down into the substrate, some folks say those grab nutrients, other say no, they only feed from the water column... But it can't hurt and I like the look of it and this tank didn't have enough substrate anyway.

What I didn't expect, was that it brings out Oliver's colors! The red-brown in his fins look real nice against the browns of the clay substrate. He doesn't seem bothered by the change. I tested the pH after adding a few handfuls of the stuff and it's now at 7.5 which is significant but not a huge jump? (I've read of it going down instantly from 8 to 6) so I'll keep a close eye on it...