Can I change gravel to sand with fish in the tank?

[spekulatius]

And lots of other questions

I've always had gravel but find it impossible to clean properly and plants don't stay down. So I want to put sand instead but what do I do with the fish? I also need to plant it again as I went away for a week and DH forgot to feed the fish so they've been eating the plants. The Java Fern leaves have turned brown, would that be because DH also didn't switch the light on during that week?

The Anubias is growing a lot so I need something else for them to grow on, any ideas? Fish shops seem to sell massive pieces of wood or rock.

And for some reason one of the old Platys died last night. He's massive, I thought it was the mother and she's pregnant but now I'm thinking maybe it was sick? How old do they usually get?

TIA

Anubias can be grown on cobblestones (make sure they are fish safe ones), so you can make a group or just put in a couple and trim the anubias when you need to.

Your DH didn't put the light on? And he didn't feed the fish?! Bad DH! You could put the lights on a timer and get an autofeeder if he's not great with looking after fish.

I'd be tempted to just put the fish in a bucket while you change the substrate over. It's only likely to take a couple of hours at most, so they'll be fine. There's a risk that there's anaerobic patches under the gravel so best to be on the safe side and take them out, and also do a pretty much total water change too.

More important is keeping the filter running. I would put that in a bucket too so it doesn't end up with grit in the impeller.

PLatys aren't especially long-lived fish, I think under 5 years is pretty normal. Any symptoms?

I think you will need to keep a careful eye on your water parameters after, too. Your filter is colonised with bacteria and mature, but part of the bacteria that live in your tank is all over the surface of that gravel too, so you may have to do extra water changes to compensate while everything stabilises too.

My platy lived to be 19. I don't think they usually make old age, though.

The Platy was about 3 years old. No I honestly thought it was pregnant and I set to my husband how can he not feed a pregnant fish. Last 2 days it stayed on the top in a corner next to cleaning magnet so I thought she was getting ready to give birth and wanted to be left alone

I'm gonna get a bundle of plants from Plantsalive but that will arrive in about a week's time. I've just seen both Assassin Snails, they usually hide and I have not seen them both at the same time, can I take them out know and keep in a bucket until the plants arrive and I can redo the tank?

Assassin snails are hardy so they should be fine in a bucket until you do the substrate change.

Definitely remove the fish to a bucket whilst you do this. There's no need to keep the filter running if it's only a couple of hours, just move it to the bucket to keep it wet but don't have it running or your fish will be in a whirlwind and may get injured.

Make sure the sand you put in is well washed. I find it easier to lay the sand in a completely empty tank. Put a large plate on top of it, and on top of that a cereal bowl. Pour fresh, dechlorinated water into the bowl (it will overflow onto the plate and then gently over the sand without causing too much disturbance and clouding the water). Then fill the tank. Get it up to temperature before returning the filter, and then the fish.

I changed the gravel to sand yesterday, the water is still not clear, will that settle with time? And after how long should I do a water change?

Yes, it should settle in a few days. You can do a water change whenever you like :) Have you tested it?

Not yet. Going to today. I mean to get rid off all the dirt that was in the gravel. I had to leave some water in the tank as I was too stupid to catch all the fish. So that water was really dirty. But hopefully will have gotten most of the snails out.

Change the water. Job done.

You can do several 50% water changes over several days to clear it. This is important if your fish were exposed to anaerobic bacteria in the gravel.

Changing water won't harm your cycle our fish so long as you dechlorinate it and match the temperature.