Help with tank upgrade

[Jamie morine]

So i have a 75gallon and i plan on upgrading to a 170gallon.

If i buy more rock and cure it in a container will i need to cycle the new tank?

 

[RobZilla04]

Welcome!

No you will not cause another cycle. Utilizing the same sand (transferring from one tank the another) typically causes the spikes associated with a cycle. Basically all the trapped nutrients and gasses are stirred up combining with a significant bacterial die off. This results in the inability for the new system to process the nutrients effectively before they reach toxic levels. In many of these cases, not all, the toxicity levels can kill some livestock. You can rinse your old sand if you choose to reuse it.

I've upgraded to larger tanks, both mine and friends, and have always added additional live rock. In some cases additional dry base rock was added as well (not in significant volume) with no issues.

 

[Popeye]

I'm currently getting ready to do the same thing. So you're saying do not add old sand? Get new?

 

[RobZilla04]

I'm currently getting ready to do the same thing. So you're saying do not add old sand? Get new?

If your tank is young (<6months) you can just transfer the sand over. If older than 6 months, rinse your current sand if you want to transfer it or get new sand.

 

[Popeye]

Yea, it's about 5 years old. I was reading somewhere to add a cup or two of old sand. I do plan on using all new sand though.

 

[RobZilla04]

Yea, it's about 5 years old. I was reading somewhere to add a cup or two of old sand. I do plan on using all new sand though.

Yes, a cup or two of the old will transplant the live bacteria to seed the new sand. Since the bacteria only populate the top 1/2" to 3/4" of the sand bed, moving all of it will only bring the detritus and sediment with it. Stirring all of that up is what drives a nutrient spike in the new set up.