In the process on setting up a small 2 footer for growing mainly plants with a school of something small (maybe 15 fish like harliquins) to add a bit of interest and create fertilizer. I have two buckets of of pebbles but they are quite large and predominantly light browns and white. I prefer a much darker substrate. Yesterday I was Mitre 10 and the guy gave me a handfull of "gap 7" paving substrate.

When its wet this stuff looks fantastic - almost black! It is however quite "sharp" not nicely rounded like "proper " aquarium gravel. but at $5 (i think) for a BIG bag - 20 kilos? It surley worth considering.

I left some in a basin overnight and the ph is slightly lower than the tap water i put in ( 7.8 from the tap, 7.2 now) GH is the same.

comments or suggestions on this or other alternative substrates... For plants should I got even finer, sand?

John.

Sharp substrate is generally pretty bad. But, could be doable as long as you don't have any bottom feeders. Finer substrate almost always looks better though.

If you want a dark substrate.. then go to Firths on Tamiki Drive.

Look among their gravels and such and you will find all the dark gravels you want.

I use "Number six".. which is around 3mm diam and after several years of use have found no probs.

Costs $32 bux a ton up here, but a sackful should cost you very little.

Bill.

Thanks Bill!

the $54 I paid for the last sackful did seem a bit steep!!

If your wanting to do a planted tank, IMHO you are better off making the bottom 1-2 inches of substrate right for the plants rather than for looks then just adding a layer (1/4-1/2 inch) on top for looks. For my substrate I use 50/50 gravel mixed with aquadic clay (purchased from a plant shop, used for lillies), and a few handfuls of peat. Doing this puts the nutirants etc in the substrate, rather than the water column where algae can access it, it will leach out for a few months but make for a far better setup.

Hey serphew, thanks for that... When you say "leach out for a couple of months" do you mean "your tank will look really murky" is it the aquadic or the peat (both) causing that?

As for months... can i buy some "right now" from some where :lol: