Old Galvanized cream tank for minnow tank

I came across an old creamery tank that is galvanized. It has a few places of rust from the years but is pretty solid. I filled it with water last night and added the appropriate amount of Better-Bait to remove the chlorine and condition the water. I have had 4-5 dozen minnows in a cooler since last weekend and not lost any,,, until I put them in the galvanized tank. I have now lost probably two dozen minnows since putting them in the galvanized tank. This tank holds around 75 gallons and I have an aerator running in it.
I guess my question is, does the galvanized tank prove to be toxic to the minnows? I have kept minnows alive in my cooler for 3-4 weeks at a time before but now that I put them in the galvanized cream tank they have started dying.

I am thinking I need to just break down and go buy a rubbermaid stock tank and go from there.

Any Ideas?

I don't know diddly about galvanized tanks but here are a couple ideas I thought of when I read your post.

How long did you wait between the time you filled up the tank to the time you added the minnows? From my history with aquariums I can tell you for sure that you need to let the water sit for a few hours minimum, just to let it "air out". Straight out of the tap, water has little microscopic bubbles of air trapped in it and you need to give the water time to let that escape. Otherwise, as the fish breathe, those little bubbles attach to their gills and will kill them. It's a lot worse during the winter, sometimes the water will even look cloudy but it's just tiny bubbles.

Also, a dramatic temp change will shock them all and probably kill some, like if your cooler was at room temp, but your new tank was still cool.

Then, you also will want to try to acclimate them to the new water as much as you can before you dump them in. If there is a dramatic change in PH levels, ammonia, or some other chemical, you can lose some fish from that too. To minimize that, you could dump 1/3 of the cooler water into the new tank and then fill the cooler back up with tank water (with the fish still in the cooler). Wait an hour and then do it again. Then move the fish AND all the water from their cooler over to the new tank. By that point you have mixed up the water enough that there shouldn't be a huge shock to their systems when they get moved to the new tank.

Anyway, that's three lessons I learned the hard way over the years. Maybe you already knew all that stuff, but hopefully something in there was helpful to somebody.

Back when I was a college student I had a 50 gallon tank with some really big fish that got successfully moved between Topeka and Manhattan four times a year, and I had no troubles whatsoever once I followed those tips religiously.

Good luck with your minnow tank.

Quote:

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Originally Posted by Fish Taxi

I don't know diddly about galvanized tanks but here are a couple ideas I thought of when I read your post.

How long did you wait between the time you filled up the tank to the time you added the minnows? From my history with aquariums I can tell you for sure that you need to let the water sit for a few hours minimum, just to let it "air out". Straight out of the tap, water has little microscopic bubbles of air trapped in it and you need to give the water time to let that escape. Otherwise, as the fish breathe, those little bubbles attach to their gills and will kill them. It's a lot worse during the winter, sometimes the water will even look cloudy but it's just tiny bubbles.

Also, a dramatic temp change will shock them all and probably kill some, like if your cooler was at room temp, but your new tank was still cool.

Then, you also will want to try to acclimate them to the new water as much as you can before you dump them in. If there is a dramatic change in PH levels, ammonia, or some other chemical, you can lose some fish from that too. To minimize that, you could dump 1/3 of the cooler water into the new tank and then fill the cooler back up with tank water (with the fish still in the cooler). Wait an hour and then do it again. Then move the fish AND all the water from their cooler over to the new tank. By that point you have mixed up the water enough that there shouldn't be a huge shock to their systems when they get moved to the new tank.

Anyway, that's three lessons I learned the hard way over the years. Maybe you already knew all that stuff, but hopefully something in there was helpful to somebody.

Back when I was a college student I had a 50 gallon tank with some really big fish that got successfully moved between Topeka and Manhattan four times a year, and I had no troubles whatsoever once I followed those tips religiously.

Good luck with your minnow tank.

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Thanks for the reply!
I waited 24 hours after filling the tank before adding the minnows. I also use Better Bait in the water to treat it before putting the minnows in there. It was all the same water as what was in the cooler, right out of the hose. I checked the temp with a thermometer before switching them and they went from 62 degree water to 67 degree water. Surely they can stand that much of a change in temp? When I used to go swimming in the lake I remember coming across cold spots in the water and I would surely think they were at least 5 degrees different so wouldnt the minnows be able to handle that or do you think that is too much of a change for them?

Well, darn. I was hoping I might have helped ya... I'm fresh out of ideas then. Have you lost any more?

No cats or other wildlife dipping its paws in the minnow tank, right?:biggrin

Quote:

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Originally Posted by Fish Taxi

Well, darn. I was hoping I might have helped ya... I'm fresh out of ideas then. Have you lost any more?

No cats or other wildlife dipping its paws in the minnow tank, right?:biggrin

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Nope! I have it covered with a screen so nothing can get to the water.
I thought I had it all worked out until tonight. I have kept approximately 3 dozen minnows alive in that tank for over two weeks. I took those minnows (shiners) out and put them in a aerated cooler while I changed the water in the big tank. Changed the water in the big tanks and added plenty of "Better Bait." Let it sit with aeration for 2 hours. Put the bag with 2 lbs of fathead minnows in the water for an hour to acclimate them. Released them into the water once everything was the same temp. Less than an hour later every one of the fathead minnows were dead. I have been scratching my head wondering what the hell is going on here. I have done everything right as far as I know.
I have a 4 port aerator that says it is good for a 170 gallon tank running in a tank that holds around 70 gallons so there should be plenty of air. The temp was the same between the bag and the tank before I released them.

So to see if it was something in the water or maybe over aeration, I put the original minnows back in the tank and they are doing fine after an hour. I just dont know what to look for to rectify this issue! Anyone have any suggestions or ideas? I am starting to believe it is the galvanized tank unless I am missing something.

I would post a question for Craig Johnson on "ask the biologist". Maybe his fish hatchery experience would be useful in solving the mystery.:dono

Pulling a guess totally out of the air, it sounds to me like there is still chlorine in the water. Even if you shocked them with a temp or PH change, I can't imagine the entire 2# dying within an hour from anything but chlorine or trapped air... If you waited 2 hours, then you know it probably wasn't trapped air. But I could be wrong...:dono

I'm really curious to find out if the problem is actually the galvanized tank. You always see farmers put goldfish in their stock tanks to keep the mosquitos down, and they generally survive for a season anyway...