Cycling a brackish tank

Black Beard · Post by **Black Beard** » Sat Jun 02, 2007 11:24 am

I'm in the process of setting up a tank for H. rubra, and I'm having trouble getting it to cycle. Since I don't have access to other brackish tanks, I didn't inoculate my tank with any material containing the bacteria necessary to get the cycle started. Not surprisingly none of the ammonia, which I added to start the cycle, has been depleted. I was hoping there would be bacteria capable of starting the cycle present in the volcanic rock I used for the decor, but this doesn't seem to be the case. I'm tempted to tear down the tank and start over, and I'd like to know what would be the best way to do this. Can I set up the tank initially as a fresh water aquarium, inoculate it with material from another fresh water tank, and then gradually start adding salt to the desired SG after the cycle has been established? Alternatively, are the cycling bacteria present in live rock and live sand for marine tanks capable of adapting to brackish conditions? I'm also open to any other suggestion you may have. Thanks for your help.

pleco_breeder · Post by **pleco_breeder** » Sat Jun 02, 2007 9:36 pm

Hello,

The bacteria involved in cycling tanks are rather specific to water conditions, and are not capable of adapting as salinity changes. Your best option is going to be to find a fellow hobbyist or shop that can squeeze you some filter grunge. Without that option, you will probably be looking at 2-3 months to get a good START.

Withing the genera responsible for nitrogen reduction, the bacteria themselves can adapt to survive outside their range. However, they are only capable of the desired results within species specific ranges of pH and salinity.

Larry Vires

ToddnBecka · Post by **ToddnBecka** » Sun Jun 03, 2007 10:38 am

You'd have a better chance of getting viable seed stock from a SW setup. I'm not sure how much difference there is between brackish and SW bacteria, but I do know FW bacteria won't work.

badflash · Post by **badflash** » Sun Jun 03, 2007 12:25 pm

Black Beard:
Update your profile to show where you are located in the world. Someone may be local. We could them PM you about getting some live gravel.

Black Beard · Post by **Black Beard** » Mon Jun 04, 2007 4:49 pm

Thank you all for the information. I have updated my profile to include my location (Texas, USA). If someone can PM me about obtaining some gravel from a brackish tank, that would be great. If not, I'm considering setting up my tank either as fresh water or marine, getting it cycled under one of those conditions, ordering the shrimp, and then carrying out a drip acclimation when the shrimp get here. I've been reading other posts and it seems that H. rubra cannot only adapt to a wide range of salinities, but that in some cases it can do so rather abruptly. Once again, thanks!

Post by **Mustafa** » Sun Jun 10, 2007 7:18 am

Actually, many, if not most (or even all?) nitrifying bacteria have a wide salinity range. I have personally increased salinity to brackish conditions in cycled freshwater tanks before without losing the cycle. Here is just *one* of many papers that will provide evidence of nitrifying bacteria salinity adaptability (in this case Nitrosomonas marina, which can live in both freshwater and sea water):

http://www.blackwell-synergy.com/doi/ab ... alCode=fem

As several species of nitrifying bacteria seem to be present in any given freshwater tank at any given time, as salinity increases the species with the best adaptability will take over.

The Fisherman · Post by **The Fisherman** » Sun Jun 10, 2007 9:42 am

Mustafa wrote:Actually, many, if not most (or even all?) nitrifying bacteria have a wide salinity range. I have personally increased salinity to brackish conditions in cycled freshwater tanks before without losing the cycle. Here is just *one* of many papers that will provide evidence of nitrifying bacteria salinity adaptability (in this case Nitrosomonas marina, which can live in both freshwater and sea water):

http://www.blackwell-synergy.com/doi/ab ... alCode=fem

As several species of nitrifying bacteria seem to be present in any given freshwater tank at any given time, as salinity increases the species with the best adaptability will take over.

That is very interesting Mustafa, I had previously thought that any SG change greater than .002 per two weeks would cause the tank to re-cycle.

I'd like to read the paper but the site wants me to subscribe or pay for it...I'll have to look into that.

pixl8r · Post by **pixl8r** » Sun Jun 10, 2007 10:31 am

And it's not cheap! $39. Makes me wish I was back in college, with access to all kinds of research papers.

The Fisherman · Post by **The Fisherman** » Sun Jun 10, 2007 10:42 am

pixl8r wrote:And it's not cheap! $39. Makes me wish I was back in college, with access to all kinds of research papers.

I am in college right now...Though not in that 'area'. I'll check and see if I still have access.

Black Beard · Post by **Black Beard** » Fri Jun 15, 2007 8:52 am

I was away from the computer for a few days, so I just noticed the additional responses just now. Thanks. I was able to access the paper that Mustafa referred to from an institutional computer. If anyone is interested, just PM me and I'll forward you a copy. I've not had a chance to read the paper too closely just yet, but it seems that the authors of this article were able to get nitrifying bacteria from a single source to acclimate to both fresh and salt water. Despite the fact that the bacterial populations that took hold in the salt water system were less diverse than those in the fresh water tanks, nitirification still occured under both conditions.

Mustafa, when you converted fresh water tanks into brackish ones in the past did you increase the salinity gradually or all at once?