The Logistics Of Changing To A New Tank -- How?

[ShinySideUp]

People must have done this and I'm trying to think of the best way to do it.

At present I have two tanks -- a four foot 240 litre  (63 US gallons) and a two foot 120 litre (31 US gallons).

I want to buy a 72 x 24 x 24 tank to replace them both.

I want to keep both my fish and my filtration and the new tank has to go in the same place as the existing bigger tank; my smaller tank is in another room.

In the new tank I want to replace the sand with small diameter gravel (fed up with sand, too much trouble keeping it looking nice) so there will be a period when the water is cloudy and not very nice for the fish.

My question is long-winded but best I can do:

In the smaller tank I have

5 small zebra loaches,
4 cory's
1 x SAE 4 " long,
15 black phantom tetra's,
and if I can find them  4 or 5 tiny oto's.

In my larger tank I have

3 large clown loaches
and 2 small ones,
an indeterminate number of khuli's (no more than 5)
2 BN catfish
and 15 diamond tetra's

While I move the large tank away and put the new one in it's place, decorate, refill and wait for any cloudiness to dissipate (I can use a filter bag and another pump to achieve this), how long will the fish be able to put up with the acute and serious over-crowding that would result if I put all the above in the small tank ? Would I be in serious danger of killing some of my fish over a period of say a week? I will have both filters running on the small tank.

 

[TallTree01]

As long as filtrwtion is powerful enough and the fish won't fight a week will be fine.

 

[fluttermoth]

I think that's a bit much to cram into a two foot, if I'm being honest.
 
Have you though about plastic storage boxes? A farmer's suppliers might have something; feeding troughs or similar. Kid's paddling pool?
 
I don't think it'll take you a week, anyway. If you wash your new gravel really, really well, there'll be at most a slight haziness, which your fish should be able to go straight into.

 

[ShinySideUp]

I think that's a bit much to cram into a two foot, if I'm being honest.
 
Have you though about plastic storage boxes? A farmer's suppliers might have something; feeding troughs or similar. Kid's paddling pool?
 
I don't think it'll take you a week, anyway. If you wash your new gravel really, really well, there'll be at most a slight haziness, which your fish should be able to go straight into.

 
It is a lot I know. The only other way would be to put everything in for a short time, move the emptied tank, refill up to a point with saved water and replace some of the larger fish in it. I said a week so that I might have time to spend decorating the new tank. I suppose I could do it in two days and finish the tank decor with the fish installed. Do you think the fish will manage for forty eight hours in the small tank if I keep the lights out and everyone well fed?

 

[fluttermoth]

Could you not put everything in the big tank, once you've moved it out of the way? It doesn't have to look pretty  
 
You probably could get away with putting everything in the smaller tank, but I'd be very, very worried; your nitrate level is going to go up very quickly, and if you get an ammonia spike from a minicycle (which can happen when you move filters) you'd lose a lot of fish.
 
I wouldn't feed the small tank, if you do it that way, while it's got the extra fish in it; anything to help keep the pollutants down.

 

[Shelster]

I would plan to do this over a weekend.

Have the gravel washed ready, have your plants ready with how you want them- you can plan this in the tank when it arrives (doesn't matter if its not in situe.
Get some cheap buckets from local farmshop ie mole valley/ countrywide type of places and place a few fish in each bucket covered with towels to keep stress down and prevent them jumping.
Drain tank, just move it out of the way so new tank can go straight in. Then arrange substrate and plants/decor how you want them and refill.

You can tweak in over the next few water changes, but if you get everything ready that you need I doubt it will take long at all.

Good luck, and may I request photos of the finished result? I love to see folks setups