Petshrimp.com Discussion Forum

ToddnBecka wrote:

I'm soaking some pea gravel in sugar now. By this time next month I should have some nice black inert pebbles to show.

New one on me, would you explain a bit please?

Easy. If you soak porus rock in sugare, it will penetrate deeply after a month or so. You can then heat the rock slowly to carbonize the sugar and the rock will become jet black. This is an old lapidary trick to produce a fake black opal.

Neonshrimp wrote:By debris are we talking about shrimp waste? If we are, I can see the waste/debris on the bottom of my tank. Should I leave it at the bottom instead of removing it during water changes? Will it be broken down by the shrimp in time?

Shrimp poo will break down quite quickly but the pollution is a problem. In a smaller tank the risk of a sudden crash is high. Better to get rid of it if you don't have enough rooted plants to utilise it as fertiliser. It would be good to keep as small an amount of sand as your planting will allow. Less chance of dirt getting trapped under the substrate and it's easier to clean.

Mustafa's solution is to use dried oak leaves to absorb the nutrients and provide a growing media for bacteria that the shrimp eat. Have a read of the "Beginners' Frequently Asked Questions (FAQ)" in the articles section. This is a required read.

badflash wrote: Easy. If you soak porus rock in sugare, it will penetrate deeply after a month or so. You can then heat the rock slowly to carbonize the sugar and the rock will become jet black. This is an old lapidary trick to produce a fake black opal.

So, do you bake them in the oven? What temperature, how long? I love this idea, as it sounds a lot cheaper than the LFS gravel, and I've always had a thing for black gravel in my tanks. Also, it would go one step further in convincing my husband that I'm completely insane, which might be fun.

Warning!!! badflash also warned us in the past about letting the rock cool for a while or else they might explode or pop I too will be trying this for a new tank

I just looked at some candy-making websites and found that sugar burns at temperatures above 350'F

I'd probably set the over at 400-450. Once the sugar is completely burnt, it shouldn't really matter how long it continues to bake. I'd probably just watch it and leave the rocks in the oven for 30 minutes after they turned black.

To cool them slowly and safely, just turn off the oven and open it back up the next day.

At least this is how I would do it.

Rinse all the sugar off quickly before baking. The sugar inside the rock does the trick. Just don't rinse a long time. You can use a metal can on a hot barbeque grill. Less smoke inside.