[Poppykle]

Hi,
I currently have a 4 foot 200 litre tank which I am replacing with a 6 foot 315 litre tank. During the transfer the fish will be placed into four plastic storage bins filled with water from the tank. I will run my current filters on two of the bins, the other bins will have an internal filter (they will probably be under filtered for a this short period). Aeration and a heater will be added to each bin.

I plan on moving all of the substrate to the new tank and add substrate to cover the additional area, set up my rocks and add 100 litres of tap water set to the correct temperature and treated with sufficient Prime for the 315 litres. I will then connect the filters to the new tank. Once this step is completed I intend to pump the water from the individual bins and transfer the fish when the bins are almost empty (easier to net in the shallow water). The heaters and aeration will also be swapped at this stage. Filters will be turned on as soon as the water is deep enough. Current filters are Nautilus 1100 and an Eheim 250. I have an Eheim 1500XL which will be added to the new tank. The three filters should provide filtration for a heavily stocked tank.

Have I missed anything? I am assuming the additional 100 litres of fresh water would be the equivalent of a 30% water change as the fresh water will dilute the original tank water. Beneficial bacteria should survive in the transferred substrate and filters during the change over.

Once the fish are in the larger tank would they grow or would they maintain their current size? I intend adding additional stock once I have confirmed the tank is stable.

 

[DJRansome]

How long will the fish be in the bins?

I would put the new substrate on the bottom throughout, and then layer the old substrate on top. It has beneficial bacteria that will be happy to have the oxygen.

Put the rocks in before the substrate.

I would not use the existing water. Do water changes on the old tank until nitrates are 10ppm or less and then the fish will be happy to have 100% new water.

The fish will grow to full size whether in 48" tank or 72" tank...no difference. Since you are not changing your bioload with the move, be sure to add any additional stock in small groups and allow a month or two between additions.

Will you use your 48" tank to quarantine the new stock before adding to the 72" tank?

 

[Poppykle]

Will you use your 48" tank to quarantine the new stock before adding to the 72" tank?

That is the plan. I lost 10 juvenile Afra Cobue in one hit when I added them to the current tank, that was a painful learning experience. I just have to find a suitable location.