Cycle with Cured Live Rock

[Schgred]

This has probably been asked but I thought I would put the specifics of my tank on here to make sure I have the right plan in place.

I was given about 20 pounds of live rock that had been in an established tank for a number of years. It sat in room temperature salt water for about a week before it was given to me so I cured it for 2 weeks before I moved it to the display tank. I have a 37 gallon tank so I bought 20lbs of dry rock to go along with it. I set up the tank yesterday with the cured live rock and all filtration going, checked the parameters today with 0 ammonia, 0 nitrates, and 0 nitrites.

I'm thinking of using some bio spora to help the cycling process but I'm wondering if that is even necessary and if the cycle could be over sooner anyway because it is cured live rock.

If I use bio spora I'm assuming fish can be introduced just a few days after. If I don't use it, how long should I expect the cycle to last? I only plan on introducing 1 or 2 fish in the beginning.

Thanks for the help!

 

[kdpuffer]

Before you can call the cycle complete you need to provide an ammonia source so you can gauge how fast the BB can convert it. I'm not an expert on cycling so I don't know what ammonia to use or how much so hopefully someone else can chime in here. What I do know is that a cycled tank should convert ammonia to nitrite then to nitrate in 24 hours. My only concern for yours not being cycled is that it sat in a bucket for a while. Was there a powerhead in the bucket? When I started my 55g a year ago I used cured live rock and had no cycle but it went from the tank at the store straight to my tank.

 

[Schgred]

The Live Rock sat in a bucket for about 5 days with no powerhead. Then it was cured with a powerhead for 2 weeks. When I got it home and started the curing it smelled really bad for about 3 days. Obviously the smell was because of the die off, so that die off would have provided the ammonia source for the rock while it was curing to develop the beneficial bacteria right? I'm not going to assume that I'll have no cycle but that being said if you brought your live rock straight from the store to your tank without any cycle, that seems to imply that the cycle will be minimal for a new tank that starts with cured live rock.

I'm fine waiting a bit, but I guess I'm wondering if the waiting is even necessary.

 

[spoonman]

I would get some pure ammonia (no surfactants) and dose to 4ppm. If the ammonia and nitrIte are a 0ppm in 24 hours and you have nitrAtes, then you are cycled and can add fish.

 

[kdpuffer]

The rock I got was in an established tank for months so I know it was cured. Had mushrooms and everything on it. I also let the rock sit in my tank for a week after which I tested the water and was able to confirm my tank was ready. The concern with your rock is whether it is fully cured and has the beneficial bacteria in enough of a density to support livestock. Like spoonman said, you will want to dose ammonia then see what it does in 24 hours. If its ammonia-0 nitrite-0 and some nitrates then your good to go. It's better to do this and put off adding fish for a day than it is to add fish and have it die on you and have wasted your money. The key to this hobby is patience and testing everything. You rush things and you crash and burn.

 

[dmolavi]

What kdpuffer said...Saltwater tanks are like race car driving. The faster you go, the harder you crash.

Dose with ammonia, you can get a bottle of the pure stuff from Ace hardware for about $3 for a 1/2 gallon. I use 1/2 teaspoon in my 20 gallon tank (that only has 15 gallons of water, the rest of the volume is rock and sand).

Once you've dosed to 4ppm, measure ammonia, nitrAte and nitrIte after 24 hrs and see if all of the ammonia and 'trites are at zero. If this keeps up for a few days, then you can call the cure done *and* (more importantly) the cycle done.

 

[54seaweed]

The rock I got was in an established tank for months so I know it was cured. Had mushrooms and everything on it. I also let the rock sit in my tank for a week after which I tested the water and was able to confirm my tank was ready. The concern with your rock is whether it is fully cured and has the beneficial bacteria in enough of a density to support livestock. Like spoonman said, you will want to dose ammonia then see what it does in 24 hours. If its ammonia-0 nitrite-0 and some nitrates then your good to go. It's better to do this and put off adding fish for a day than it is to add fish and have it die on you and have wasted your money. The key to this hobby is patience and testing everything. You rush things and you crash and burn.

doing what is suggested will save you heart ach we don't tell you something if it is not necessary
we want you to have success the first time

 

[Schgred]

Thanks everyone. This is definitely helpful.

I'm curious, do people consider something like bio spira or a similar additive to either be "cheating" or possibly not worth the money? Or is it just a gimmick? Reviews seem pretty positive about its benefit of preventing spikes.

 

[dmolavi]

It adds the BB to the water, but doesn't add it to the rock. They need to grow in the rock, which takes time. Therefore, water changes will just cause them to be flushed..

 

[IslandHopper]

Schgred... you're right on ... I started a brand new tank with cured LR (50 lbs in a 90 gal tank) from a local supplier... it took about 5 days for the tank to stabilize it's ability to process ammonia rapidly (12 hours or so to eliminate a capful of pure ammonia.)

There's too many variables to say it would work that way for everyone, but using "live" live rock from the start will definitely shorten the cycle compared to the 4-6 weeks it can take using all sterile material at the start.
My experience is that a few days with your method is not out of the realm of possibility.