Done cycling?

I'm rather suspicious of my tank chemistry right now. I have a 29 biocube seeded with 16# live rock and an inch of shrimp that's still sitting in the bottom. It's been less than two weeks, and I've seen an ammonia spike, but now my ammonia/nitrite/nitrate is reading 0/0/0. There's an assortment of algaes cropping up around the tank as well. I'm wary that my tank appears to have cycled this fast. Also, my pH is 7.8, which is worrying. Recommendations?

 

with the live rock and the live sand you are not necessarly going to have a full cycle, esp if the live rock is fully cured. I would remove the shrimp from the water.

As far as the pH, I would not be overly concerned. There are so many factors that can affect a reading, mainly how long light has been on. Your pH is going to be lower when the light comes on at first, then raise with the lights. Also biocubes have a lid on it, so that can affect it. Do you have any powerheads in the tank?

 

not to contradict schackmel (I don't believe I am) but I'd leave it and keep testing for a few more weeks. It's not unheard of to 0 out and then two weeks later have another round of spikes...

It's possible it's done already, but no reason to not wait it out either.

 

I don't think I have a powerhead. I'm running the chemical and biofilters that came with the tank, the pump that came with, and a heater (currently off, as the water stays well above room temperature without it). I'm not using live sand, just live rock and a crushed coral substrate. I've been testing toward the end of the day, after the light's been on for hours.

 

+1 to this. When I set up my tank with aquacultured rock, I had no ammonia for 2 weeks (and thought I wasn't going to have a cycle due to the life already on the rock), added a clown to the tank, then 2 weeks after adding the clown had a spike due to dieoff of some sponges.

 

I agree with the above statements also! I personally never have used shrimp to cycle my tank, so that is the reason I am so fast to say yank it out........ But since your sand is not live, then I concur that you are probably not done cycling! I would maybe consider getting a hand full of live sand from your fish store tanks and add it to yours, this will help seed the sand faster!

I would purchase a koralia 2 or 3 powerhead. Biocube 29 was my first tank and I find that it does not move the water around enough IMO. Place it on the opposite of the return jet and it will really help stir up the water, which can help with pH also!

 

The algae is really starting to bloom, and I'm still at 0/0/0. If I pick up some CUC at the same time as the powerhead, what's the likelihood they'll have trouble surviving in the tank?

 

I got really lucky when I started up my tank, my cycle happened super fast, like overnight. I had 60lbs of live rock + 10 of dry rock & 60lbs of live sand. I tested AM/NI twice everyday, never saw a spike. 8 months later all is still stable & fine. I am a firm believer that really good live rock can cycle your tank extremely fast, or did I just get really lucky?

 

I'd leave the shrimp in and get a CUC if your ammonia is at zero. The shrimp is pod food at this point. I've cycled 2 tanks in the last month with a single shrimp in each tank. Both tanks are loaded with small pods now that were feeding on the shirmp, which is a great food source for your fish as they get bigger.

Another way to combat some of the algae is to include some ulva or cheato in the tank to suck up the spike in nitrates the shrimp will make as it's eaten/decomposes.

What you don't want to happen is have an ammonia source feeding the bacteria in your tank, then take that ammonia source out; reducing the bacteria populations. This may cause another cycle once you add fish.

-Hope this helps

 

I had a similiar situation with my Biocube. Placed 40 lbs of LR from an existing tank into my Biocube (purchased from someone breaking down their 6 year tank) I did keep all of the LR in water, used 10 gallons of water from LFS (the rest I mixed with RO/DI), and I did not use any sand (still do not have sand in tank). I did not have a cycle and if I did it was so quick I never read it on any of my daily tests . I did not use the Biocube filtration (still would recommend not using it). This turned out to be more inline with moving a tank then a new setup.

+1 to adding CuC, I have used in my other 2 tanks during cycling and found it beneficial.