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Cycle question


Larger Pacific Striped Octopus
Oct 2, 2009
I will be upgrading my 55 gallon tank to either a 75 or 90 gallon tank, not sure which yet. I will be buying it in bits and pieces as I dont want to buy used stuff this time... I want to get my dream system.

Anyway, my question is this... I get my water straight from the ocean. Will I still have a cycle if I take sand and rock and water from my current tank and then just add more seawater? If I do will it be a full on cycle or will it just take a week or two to settle down?

I really want my tank set up by November so I will be able to get an octo from Tom but I dont want to rush the set up. I'm just looking for info on others experience with transfers like this.


Staff member
Sep 4, 2006
Gainesville, GA
From my experience, If you use your bottom substrate, you will likely get at least a minicycle from disturbing the biologic material in the settled sand. I don't use "live" sand in my tanks but the top half inch or so of your current tank would function this way but anything beneath this will likely only transfer nitrates or rotting material. When I upgrade, I use new sand as the rock contains most of your beneficial bacteria. You will lose some of the beneficial top surface bacteria doing it this way and either way you do it a good two weeks to a month to let the tank settle in.


Dec 22, 2009
IME you can do this with minimal cycle.
I transported a 40b tank and sump after removing the sand, rock and water, 1/2 of which I used in it after set up. The other 1/2 was used to "wash" the sand - not completely, but to get the majority of detritus out. Topped system off with 24 hr old new mixed water and the system took right off. No detectable ammo or nitrate the first week. Nearly 1 yr. later system is still running w/ out any issues, in fact it has never had nuisance algae all this time.

This is a good time to bring up a point I have always maintained. When setting up a brand new system, it is extremely helpful to use some aged water from an established system - at least 1/4 volume, AND a quart or 2 of well established substrate over the top of the new substrate.
Doing these 2 things will go a long way to kick start a new system.

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