Am I safe to use old water in tank upgrade?

[2manyideas]

Rinsing will have little to no effect on your bacteria colonization. Just don't let anything dry out.

Do you have new sand for the tank, or planning to reuse?

Either way, plan to wash it prior to putting it in the tank. Hose +bucket + spray nozzle works great for this.

I am more than likely going to reuse some of the sand and buy some more to save on costs so I will apply a similar technique. I’ve said it a bunch but you have helped immensely.

 

[Lost in the Sauce]

I am more than likely going to reuse some of the sand and buy some more to save on costs so I will apply a similar technique. I’ve said it a bunch but you have helped immensely.

My pleasure. That's what this place is for.

If you haven't yet, take a look at the Sand rinse and reuse thread.

There's a lot there, so here's the TLDR

-once the tank is empty of water, gather your sand in 5g buckets (Do Not Use Bare Hands). I fill them no more than 1/2 up.

-Grab a chair, you'll need it. Using your lawn hose and spray nozzle, agitate the sand. The water will be disgusting.

-Once the water level is up to the top of the bucket, tip the bucket removing most of the disgusting water while retaining the sand.

-Do this over and over and over until your bucket is just filling up with clean water.

-RODI rinse sand and add back to the tank it's going in with flow off. I use a 3" PVC pipe to drop the sand all the way to the bottom without clouding.

Start up circulation/filtration.

 

[sfin52]

Thats how I started my bosses tank and my 120. I saved water from the 90 and 55. Upgraded 55 to the 120. Helped a ton on getting water and saved me money

 

[Duncan62]

Speaking of the rocks, can I do a quick rinse in RO/DI to knock off loose algae particles and detritus etc and still use them for beneficial bacteria or will rinsing them remove the bacteria too?

I brush and rinse in sw.

 

[Cell]

I am more than likely going to reuse some of the sand and buy some more to save on costs so I will apply a similar technique. I’ve said it a bunch but you have helped immensely.

Reusing sand is not recommended unless you rinse it until it's like new before re-adding.