concrete

So I wanted to show the progress I made on my rock build 24 x 18 x 24 Exoterra. The system was built to have a small pond and an waterfall/stream that feeds into it. The pond has two drains at the water line that also act as a protein skimmer to avoid protein build up on the surface of the...

Does anyone know what kind of concrete you can use to make a waterfall or background in a vivarium? I've heard concrete leaks out substances that are bad for the plants and darts? How do you make the concrete "viv safe"/ keep it from leaking the bad substances before you put it in? Different...