Switching Substrate

[JustKia]

Not knowing that you could use sand in an aquarium (it never crossed my mind) I opted for small gravel - it's ~2-3mm but not round like pea gravel.
I'm still cycling for now and I'm loving all these tanks I see on here with sand as a substrate.
If I decided to swap would I be best to wait until the cycle completes or do it now before there's optimal bacs in the substrate (I know most will be in the filter, but there's surely some in the substrate?)
And how do I get the wet gravel out?

 

[drobbyb]

I'm not sure on if it will affect your cycle. My thought is that you will probably be ok, but wait for someone who knows for sure.

You are going to need to drain the tank as low as you can get it. Then remove all ornaments, large rocks, and decorations. The best way to get gravel out is with a small clean dustpan and just scoop it out and into whatever you want. It's going to be messy. If you are going to wash your sand before adding it to the tank, this would be a good time to do it After all the sand is washed and free from debris, scoop the sand out of the bucket or whatever you used to wash it in and place it into the tank. Smooth it out and fill with water (using a plate to diffuse the splash will help keep your sand where you want it.) Make sure all the sand has settled before starting your filters.

 

[rdd1952]

Changing substate won't affect your cycling unless you have an undergravel filter and if you do, you can't use sand so I assume that isn't the case. If you don't have fish yet and are doing a fishless cycle, my advice would be to simply wait until the cycle is complete and when you do the large water change just change substrate while the water is out. Simply scoop it out with a cup or something like that. You can most likely syphon it out too. If you take a gravel vac and remove the vacuum end so it is just the hose, it will probably syphon the gravel. I know it works on sand as I have done it before.

 

[OldMan47]

A substrate swap while cycling means giving up any bacterial colonies thatmay have started to establish in the gravel. Although most of the beneficial bacteria are in your filter, some usually also develop in the substrate.
The process is easy as DrobbyB said. Just drain the tank most of the way, don't forget to switch off the filter and heater. Remove the old substrate and replace it with well washed sand. I prefer my sand about 1 to 1.5 mm diameter but that is a matter of taste, not necessity. Washing the new sand is probably the hardest part because the better you do it, the more likely you will enjoy the sand substrate in the long run. Let the dirt that got into the tank settle before you switch the filter back on if it is one that has an unfiltered pump impeller. Most hang on back filters have nothing to keep the sand out of the impeller so it can be a fine balance between keeping the filter well cycled and not ruining the impeller by sand grinding it up.

 

[JustKia]

Thanks.
I know I'll be giving some bacteria up, but I was figuring that seeing as I don't yet have a full colony of bacs then I'd not be giving up as much as if I waited - but of course always good to get a second opinion.
I'm fish-in cycling (I know it's not the recommended way, but I'm quite happy to be doing plenty of tests and water changes as neccesary), so I'm thinking fish and filter in one bucket of tank water - cover with towel and put in cat free room, plants and ornaments in another bucket of tank water, sand in 3rd bucket with hose running through it while we siphon off the rest of the water. Actually getting the gravel out will be the trickiest bit I think but dustpan sounds like a good way of scooping the gravel - will have to try that one.
No, undergravel filtration, just a fluval 3+ that came with the tank.

 

[OldMan47]

The Fluval internals are fairly well protected from the sand by the sponges on each side so you should be able to start the filter running almost right away.