Attempting to make some caves using poly and concrete, got on well last night but today the concrete must be drying to fast as its not sticking to polystyrene... All being well these will go in the big tank with the Zebras...

Gill

Hi there,

just make sure you leave it for about 14 days to cure 100% and then put it into a bucket of water that you change often until it wont push the pH anymore. Otherwise the same will happen in your tank and a pH of 8 or 9 isn't really pleasant for most fish...

Cheers,

JaSa

What sort of "concrete" are you using? you'll need more of a plastering mix. Try a mortar with maybe some extra cement, plastercising additive or bonding agent which is a bit like PVA. Id just try some extra cement first.

I would really seal that before putting in your tank. Who knows what chemicals are in the concrete and I've noticed pH leaking for A LONG time with concrete in water.

I have flagged making them ,i don't like the look or the idea of using poly and cement,so went to Stone and Water world got some nice alpine rocks/slabs...in the process of using some aquarium safe sealant to secure before adding to tank..

Gill

You could also try using pumice rock as it is very easy to shape into a cave.

You could also try using pumice rock as it is very easy to shape into a cave.

Once you get over the floating issue?

Also algae absolutely LOVE pumice rock for a growing surface.

Once you get over the floating issue?

Also algae absolutely LOVE pumice rock for a growing surface.

Boil it, it will then sink - most of the time

Moss/Fissidens also loves pumice