Using 'just Cycled' Tanks Old Water...

[bogwood]

My tank is newly cycled and I'm doing the large water change today to remove the nitrates before adding the first fish.

Can I put this 'old' water into another new tank - to help speed up this second tanks 'cycle' - or are there minimal bacteria present in the water? (I cannot add any substrate or filter media from the first tank to the second).

 

[annka5]

There's not much point in adding the water as it contains almost none of the beneficial nitrifying bacteria. It'll not speed your cycle any IMO.

 

[bogwood]

There's not much point in adding the water as it contains almost none of the beneficial nitrifying bacteria. It'll not speed your cycle any IMO.

Thanks!

 

[rdd1952]

Annka5 is correct. There isn't any beneficial bacteria present in the water. You'd just be adding dirty water to your new tank. Try moving a little of the filter media from the cycled tank to the new one. That would provide the seed you are looking for.

 

[cashton]

Annka5 is correct. There isn't any beneficial bacteria present in the water. You'd just be adding dirty water to your new tank. Try moving a little of the filter media from the cycled tank to the new one. That would provide the seed you are looking for.

You can also take the filter media from the new tank, place it in the filter of the cycled tank along with the cycled tank's media and the bacteria from the old media will seed the new media, but this will take a good week or two to get enough growth to do any good, so it might not really be any faster to do this.