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Sand sub. Grow bacteria in dif tank?

966 Views 4 Replies 2 Participants Last post by  Diana
Hi everyone, i have a 55 gl tank with a gravel substrate. I wanna take on yhe challege of plating this tank so my task is to switch to sand or sand like media. I really would like black for the color so any suggeztions would be much appreciated! So the guy at my lfs told me if i were to do that then my tank would basically go through a new cycle. So what i was think was basically cleaning the sand then cycleing it in a dif tank with the plants and such growing in it to basically growing the bacteria and growing the plants at the same time... Any thoughts and suggestions would be nice
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Here is a thread in which I just answered that question: What happens to the nitrogen cycle when you switch tanks, including new substrate.

Your pet shop guy is wrong, or at least not complete in his info.

Old style, under gravel filters would grow a really substantial bacteria population on the gravel, especially when there were no plants. Plants are a great bio filter.
New filters (HOBs, canisters, sumps...) grow about 50% of the bacteria that is in the system. About 25% is in the top layer of the gravel, but not deeper. These bacteria need oxygen, and there is not enough lower down unless you are running the old UGF system. About 25% is all over the tank on surfaces including the leaves of the plants, the driftwood, the rocks and the equipment. Feel how these things have a slimy coating? That is the bio film where the bacteria live.

Nitrifying bacteria may provide less than half the ammonia removal in a well run planted tank, and a very densely planted tank can get by with just a little bacteria.

When you change substrate follow the instructions in that other post, including getting some Nitrospira 'just in case'. Do not let the pet store folks sell you something else 'just as good'. Do not waste your money.
Another way to save some bacteria is to skim the top most layer of gravel and save that in 3-4 mesh bags.
When you are setting up the new tank hang these bags in an area of good water flow. Remove the bags about one per week as long as the tests are good. This will ease the loss of the bacteria, spreading it out.

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Another part of the answer to the first question:
Yes, you can do a fishless cycle in a bucket of sand. Part of the problem is that there is not a lot of oxygen lower in the sand, and when you move it to the tank you may not have the higher bacteria population at the top of the substrate.
Suggestion: Do the fishless cycle in a shallow container, perhaps a plastic storage box, and only use 1/4 of the sand.
When you set up the new system put the non-cycled stuff in first, then put the cycled sand on top.

Where to find black sand:
1) Eco Complete is a good planted aquarium substrate that looks like black sand. Coarser, though.
2) Tahitian Moon Sand is very expensive, but is absolutely black.
3) Swimming pool product by Pebble Tek is added to the finish inside a pool to make it any color you want. It is fine quartz bits. Completely aquarium safe as long as you avoid the product line that has real sea shells in it. Mostly blended colors, so the black might actually be about 75% black blended with whites and greys.
4) Try brick or masonry yards. Some may have something that will work for you.
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