Upgrading Tank Size

[CubanHogFish]

Hi i got a question of how do i go about upgrading my 75g DT to A 125g DT, Well the question really is im planning to use everything in the 75 DT to the 125 Dt but i dont know if when i do that is that going to cause the 125 DT to go into a cycle even if i use the water,LR and sand that is in the 75 DT right now i have fish and other critters in here. or should i buy everything fresh leave the 75 alone and start from the beginning

 

[Jimbo662]

If you're moving all the rock / sand there shouldn't be an issue. The beneficial bacteria will already be there and will just begin to multiply and the new rock / sand. I'm in the process of setting up a 175g and will be moving all the contents of my 50g cube. I'm also adding a bottle of bio-spira just to add additional bacteria from the start.

 

[143MPCo]

...you will get a cycle of sorts, you're kicking up whatever trapped material you have either in the sand bad (if you have one) or in the nooks and crannies of the live rock. That's not to say you should buy everything new and cut over that way but, you will want to try and trap as much of the organics material as you can out of the tank water before moving it over.

I used a mag drive pump, vinyl tubing with a 50mm sock zip tied to the end of it, as you remove all the live rock shake it off in the old tank water removing a much of the trapped organics material in the nooks and crannies... next filter the old tank water via the pump and 50mm filter on the end of it into whatever containers you have... if you have sand leave enough water to keep it covered as you scoop it out and into either the tank or a container, use a little filter water to keep it covered and don't allow it to get too cold.

I know of some that used a diatom filter to clean (polish) the water and removed everything before reusing it in the new tank that's also an option.

Next is test, test, test... if you don't keep the critters you have to a holding tank for the time being and even if you do you need to test the ammonia level in the new system but, if the rock used was cycled you might not see a spike at all, plus letting the tank settle before adding the critters back is recommend. Just keep them warm and air/water moving in the holding tank.

 

[CubanHogFish]

I have a 40g breeder QT that im planning to put the critters into but o dont think keeping them there to long os a good idea since i have tangs and other fish that like to swim. I want to keep the stess levels as low as possible i was thinking maybe a day or 2 until everything settles but im kind scared of a cycle happening after that and killing everything ( including corals and bubble tip anemone)

 

[MOPAR]

If I were to do it I would use fresh sand because as posted above the old sand will be filled with a lot of organic material. Then over a series of weeks let the new sand cycle and do small water changes to the 125 from the 75 often to balance the tanks. Once you feel the 125 is on par with the 75 move the rock over. Keep livestock in the 40 for a week or so to feel out the 125 then transfer. The week in between will also give you time to really get your scape down.

 

[RMS18]

I went from a 20 gallon to a 30 gallon.. I did NOT use my sand and bought brand new fiji sand. I also used only 15% of my live rock the other 85% was brand new live rock. I did use almost all my old water I left about 2 inches as I didn't want to suck up any of the sand. I never had a mini cycle, I used the same filter media, mine however was fishless as I had them in a qt tank for ich. I only was feeding the corals and inverts. You might go through a mini cycle due to the big increase in the upgrade. I also added live bacteria, the refrigerator kind not the stuff in petco.