[dmc123]

I have recently recived a 75 gallon tank as a gift. I currently have a very successful 30 gallon tank. My plans were to basically do water changes over several months to help start the new tank start establishing the same bacteria and such as the tank that my fish are now in. I also currently run standard filters and am considering going to a canister filter. What are the pros and cons of both?

scary as it is I have all my original fish minus two that died when i had a heater failure. Should I add 10 more fish before adding my current fish once my tank has cycled? Or wait until after i add my current fish.

 

[dielikemoviestars]

If you're just transferring your current fish to the new tank, move the filter over and you're ready to go. The tank will be cycled. If your tank came with a new filter, run it on your old tank (with fish in it) for a few days then transfer everything to the larger tank. You should be able to add a few fish at that time, too, but you might want to wait a day or two just to make sure everything goes well.

 

[DGT]

Moviestar's suggestion should work. If you really want to know what is going on, invest in a test kit and keep track of the ammonia/nitrite/nitrate levels. Running the filter on the existing tank with fish in it (an ammonia source) will establish the bacteria necessary to convert the ammonia produced by the fish into nitrites and nitrites into nitrates.

By standard filters, I assume you mean the hang on the back variety. There are pros and cons to various filter types. Some folks run both types together. Flow rate and capacity is important. I use a single Eheim 2217 on my 55 gal with good success.

Dave

 

[PfunMo]

Lots of small things that we don't know may be important. Normal thinking would say that if your filters are doing okay in the 30, they will do fine in double the water. Same amount of bio-load with twice the water to dilute it. But then there is some bacteria that you need in the gravel, etc. in the old tank and some of that will be possibly lost. Still should be okay. Changing the water only over several months may not do that much for you. It is not the water which needs to cycle but the beneficial bacteria, much of which is in the filters and the rest in all the other parts of the tank. Just moving water and letting it set will do nothing for building a bacteria colony in the new tank. They build up when there is ammonia from waste. Without fish in the new tank- no ammonia. Move the fish ,water, and filters and much of the bacteria moves with them.
For adding new fish, it depends on what fish you have and how they feel about new folks in their tank. What I do is move the fish, see that all is well by testing the water for a while and then rearrange bunch of the decor in the new tank and add the new fish. This makes the old fish as lost as the new fish and they are more likely to get off to a level start. All this depends on what kind and size fish.
I like this explanation of what's happening with the water:
http://www.freshwater-aquarium-fish.com/water_chemistry.htm