brackish to full marine?

[JGoslee]

I have a 15gal brackish tank that I want to convert to full marine. The only problem is that I have a figure eight puffer in the tank. Will bringing the specific gravity from 1.010 to 1.023 kill all my bacteria and cause a cycle? Right now the tank is being filtered by an aqua clear 70 with sponge and ceramic rings. After I bring the SG up to 1.023, my plan is to replace the sponge and ceramic rings with live rock rubble and add 20lbs of fully cured live rock to the tank. Does this sound like a good plan or am I missing something?

 

[j0tca]

hmm,

What you are suggesting is a major change in the system. I wouldn't expect the puffer to live. Such a change will not kill all the bacteria but I would still expect some minor amonia cycling to occur.

Overall your plan should work. I would keep the sponge though, it's needed. My real suggestion to you is to start reeding about small tanks. A 15G marine tank is fairly hard to do well since the water volume is so small. Small changes can have sudden, and large consequences since there is no water volume to act as a buffer.

Good luck

 

[JGoslee]

The main thing Im trying to avoid is the tank recycling. Over the past week I have changed the tank from freshwater to brackish. From what I've read the change in specific gravity won't kill the puffer. They are very adaptable.

 

[DizziDezi2]

you have to do it slowly- you cant add it all at once- add it over a few weeks.

 

[Asuran]

Figure 8s dont do well in full marine conditions if you have green spotted then it would be ok... you can try though... but just raise salinity slowly at .02 a week. I did that with my pair of green spotted puffers and just added in some live rock last week they are seem to enjoy picking at the new liverock

 

[JGoslee]

I did a search on figure eight puffer's, and from what I read there are alot of people who had them in full marine conditions. Actually there was one person who had one for 12 years in a marine tank. Raising the salinity slowly does make sense. Is the tank going to recycle from the salinity change?

 

[j0tca]

yes and no, cycling is too general a term to describe what will happen when you raise salinity. If you raise it slowly, the system will have a chance to adapt to the new conditions. If you raise it quickley, who knows?

 

[moses13]

I had a green spotted that I started in fresh and migrated to full marine. He lived about 8 years. Do the changeover slowly enough and the bacterial population will change with the salinity change. A few weeks to complete the change sounds about right.

 

[JGoslee]

What would be the lowest specific gravity that I could add the live rock?

 

[j0tca]

Interesting question....

I would say that it depends on how many hitchiking organisms you want to live on the rock. To truly preserve good quality LR, which in my opinion brings in most of the life of a tank, I wouldn't add it earlier than 1.023. Now, if you are buying base rock from a lfs that has little or no life already on it, It would probably have little die off at 1.018. This is all conjecture and an estimate.

Personally, from extensive experience trying to do things too quickley, I would say wait. Raise the salinity over a few weeks, then slowly add your rock. It will be worth it in the long run by how much more life survives in the tank and fewer headaches.

 

[toonces]

keep in mind that people DROP their salinity from 1.025 or so to 1.009 when doing a hypo treatment...often fairly quickly.

if you go slowly in the other direction, i wouldn't stress too much. the tank will adapt. something like .005 a day would probably be ok.

 

[JGoslee]

If I raised my salinity .005 a day, I would be at 1.025 in 3 days. You don't think that would kill all the bacteria in my filter?

 

[moses13]

I think he meant .0005

 

[j0tca]

Um, toonces, you're not supposed to EVER drop the salinity in your display tank. Even in a FO, dropping salinity in your main is considered bad. It causes dieoff which could lead to an amonia spike. Your display tank is supposed to be teaming with life. The purpose of a QT/Treatmet tank is that it's barren so you CAN play games with salinity.

When doing Hyposalinty, you use a QT and match the salinity in your main before adding livestock, then you slowly drop over a few days.