Zinc

[Finn]

I have noticed a few posts about galvanizing being toxic. I didn't really believe that as I have seen numerous galvanized water tanks and watering troughs, I even have an aquaponics book (Wish I would have bought yours Gary:()that the author's fish tanks and grow beds are galvanized steel. I went and did some research and this is what I found:
Basically the element itself is not considered a hazard and is necessary for good health(we have approx 2.3g in our body), but some zinc compounds are (zinc arsenate or zinc cyanide for example).
Here is a link. This was the best explanation that I found.
http://www.lenntech.com/elements-and-water/zinc-and-water.htm


Finn

[fishfood]

If its the book i am thinking those tanks a aquaplated actualy lined with a spray on plastic[ kind of, dont know the process]

[Dufflight]

AP water is acidic. And most rainwater tanks were also concrete lined.

[Crusty]

I have noticed a few posts about galvanizing being toxic. I didn't really believe that as I have seen numerous galvanized water tanks and watering troughs, I even have an aquaponics book (Wish I would have bought yours Gary:()that the author's fish tanks and grow beds are galvanized steel. I went and did some research and this is what I found:
Basically the element itself is not considered a hazard and is necessary for good health(we have approx 2.3g in our body), but some zinc compounds are (zinc arsenate or zinc cyanide for example).
Here is a link. This was the best explanation that I found.
http://www.lenntech.com/elements-and-water/zinc-and-water.htm


Finn

Zinc (as with most heavy metals) becomes primarily more toxic as your pH. gets lower. The other is your calcium hardness, metals become more toxic below 150ppm hardness and higher than 300ppm. Fish suffer from the accumulative affect of metals and different species have very different and wide tolerances to different metals. Zinc in this case does have a primary negative effect on reproduction in most fish. My understanding is most APs appear to run at low pH. (more suitable for plants, not fish) the risk of issues with heavy metals, especially if dosing for plant growth will increase as the system water gets older.

Just an observation....

[Outbackozzie]

And an observation that you are correct in.

We dont post about things like copper, zinc, lead etc being included in the system as being bad for no reason. Fish have died from metal poisoning.

Every single system that I have seen in all AP forums, that use non-lined galvanized tanks, fail after 6 months running. Massive fish deaths for no reason, except for the tank and growbed materials.

[Jackalope]

I know this is an old thread, but I have a question or two about these metals ...... I suspect that my system has both Zinc and Copper in the water ..... I was thinking about it today .....

1. My town water system uses an 8" PVC main, but the saddle I put on the main to get the water from the main, is brass, as is the corporation valve. Then, the water flows through 20' of 3/4" ID copper tubing (per code, no choice about it) to get from the main to the brass curbstop valve. then the water flows through a 1" plastic pipe for about 90' to another brass mainvalve in the building, before I separated it into the several takeoffs that feed the various rooms and water appliances. So my question about this is; is that enought copper/brass exposure to kill my fish ..... I've lost three in the past 2 weeks, but nothing for quite a while before that .........

2. I've used some runoff water from the roof (when I first started and lost quite a few fish) that comes off a galvanized roof which is patched in some places with a tar/asphalt/or something like that, roofing patch compound ..... is this too much exposure to the Zink stuff to poison the fish? I was blaming their deaths on the LFS which didn't use enough oxygen for transporting the fish 110 miles.

3. Is there anything I can do to remove the copper/zinc from the water before putting it into the fish tanks?

Thanks, I'd like some opinions for my personal reference ;)

[Ravnis]

the tar/asphalt would be something I would really suspect. Water conditioners for aquarium are supposed to remove the metals as well.

When I was adjusting my pool ph I had to be careful not to get it above 8 as then metals would precipitate out of the water and onto the pumps. So that might be a helpful factor. I use tetra aquasafe, because I have no Idea what stuff is in the water besides the 5 ppm of chloramine.

[Jackalope]

the tar/asphalt would be something I would really suspect. Water conditioners for aquarium are supposed to remove the metals as well.

When I was adjusting my pool ph I had to be careful not to get it above 8 as then metals would precipitate out of the water and onto the pumps. So that might be a helpful factor. I use tetra aquasafe, because I have no Idea what stuff is in the water besides the 5 ppm of chloramine.

Just to let you know, the tar/asphalt/galvanized roofing are not yet a concern, but would have been when the rainy season gets here ;)

I didn't think of the conditioner, since I'm keeping chemicals out of the system, I've only used the conditioner to remove Chlorine/Chloramine in an emergency situation ...... other than that, I just let the water sit for 24 hours ........ I'll take a look at the label to see if it's good for taking out the metals ....... this product is Start Right by Jungle Laboratories in Cibolo, Texas ( Your neck of the woods ;) )


Makes water safe for fish immediately. Reduces stress, removes chlorine and chloramine, neutralizes harmful metals, stimulates fish slime coat naturally, adds beneficial electrolytes.
<snip>
Active Ingredients: chlorides of sodium and potassium, allantoin, polyvinyl-pyrrolidone.

I wish there were some way to do this organically, I suppose the sodium and potassium are good, but the skin conditioner (allantoin) and the poly-whatever don't sound real great to me .........:rolleyes::rolleyes:

[Crusty]

Is there anything I can do to remove the copper/zinc from the water before putting it into the fish tanks?

Hi Jack

Water through you pipe work and fittings will not be of any great concern, unless your water is acidic, which I doubt. It is good practice to use some form of activated carbon (GAC) filter for any source water being introduced to your system. This will take care of any toxins, metals of concern.

[Jackalope]

Thanks crusty, I guess I should have a carbon filter for the water .... I only use carbon filters for the fish and crawdads ;)