Not sure where to put this question, doing a brackish to marine conversion.

I have always kept m tank on the higher end of brackish but after a lot of thought and reading I have decided to convert m brackish 90 gallon tank to full saltwater. I have gotten rid of my figure eight puffers as I was told without a doubt that they can not handle full marine. I still have a mono, banded archer, dragon "violet" goby, 2 knight goby and my columbian shark. Once a week I pull 30 gallons out for a water change when I mix my water the night before all I've been doing is adding a little extra salt. I mix 5 gallons at a time in a bucket and have only been adding about a Tbs extra salt each bucket, watching my salt in tank and tote to make sure its not to much at once to stress the fish. I figure at this rate it is going to take me till May or June till I get it to marine and at least 3 - 6 months after that before I declare my brackish fish full marine.

Now my question is has anyone here done this before and am I going about this correctly.

The salt I am using is a mix of instant ocean and on every other water change I will use instant ocean reef crystals. I do that mainly because I would like to add live rock to the mix and eventually once the tank is matured some soft coral. My salt right now is hovering right around 1.019 - 1.020 right now. It jumped a little more that I wanted on my last change. Not sure if I miscounted when I was adding the salt or what. I have been watching the fish close and they do not seem to be bothered. My mono is showing more life than normal actually playing and darting about the tank. As long as everything is stable next water change and we r still running near 1.020 or higher I will add a few pieces of live rock next change and a few more each week after.


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Khemul said:

I'm curious on that too. The Colombian Shark, Archer and Mono should be able to handle it. The Gobies I'm not so sure about. I doubt the Knight would make it. The Violet is a toss-up, since it is a pain to get any real information on them, but they are generally considered low-end brackish so I'd guess they'd be similar to the Knight.


Otherwise the process looks fine. Might be a bit overly conservative on the rate of change, but then those Gobies may need it if they can survive salt. The others are adapted for relatively rapid changes in salinity (which isn't to say one can shock them, just that they'll take it better then the Gobies will).

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I am not sure about gobies either that is part of why I am going slow. I started on the higher end of brackish so I am already close three weeks later. But I slowed it down after things with my puffers started going bad. I want to get it to 1.020 and leave it there for a few weeks at least before I increase it again. Plus that will give me time to add some live rock and help keep my water stable through this. Least I'm hoping that how it will work lol


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TL1000RSquid said:

Violet is suppose to be able to take full marine conditions, Knight im not so sure about, I always thought they lived in low end brackish and even freshwater.

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Its driving me nutts because I keep finding contradicting info on the knight gobies. One web page will say they thrive in low end brackish but can live in marine another will say never marine can stand brackish and thrive in fresh. I have a smaller brackish tank still up and running just in case things go south, I by no means want to kill my fish.

TL1000RSquid said:

You could probably bump up the conversion faster if you wanted upping total tank salinity .002 per water change depending where you're at now, Whats your salinity currently at?

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I did as us suggested and add extra salt to the mix today and bumped it up to 1.022 and added about 30lbs of live rock. I know they should be fine but been nervous today watching my fish. Everyone seems happy so far, even the knight goby. I haven't had any major changes to the water quality yet, tested tonight and my ammonia and nitrates have gone up a hair but not to a dangerous level. Oh I did also add the live culture additive instant ocean offers, bio-spira I think is what it was called. I'm not sure if I needed it but figured it wouldn't hurt either.