Black Spots again... Maybe found the culprit?

[Icewall42]

Hello again. I had a lot of trouble with black spots all over my clowns some months ago. They recently showed up again in force after I tried a salt bath. The salt bath worked, but as soon as the content dropped below 1000ppm, the spots came back. As a last resort, I had all the carbon removed from the filters.

The black spots are now gone again, even as the salt content is falling to a more normal ppm.

I've come to the conclusion that one way or another, the carbon I was using was the culprit of the black spots. My mother, also a fish expert, agrees that this was the trouble. It must somehow be connected since all the spots are now gone again now that no carbon is in contact with the water.

Thoughts?

Also, all 12 of the clown loaches are fat, happy, and beggy! Just wanted to let you guys know that the new clowns I recently received from a fellow LOLer are doing well.

[loachmom]

Also, all 12 of the clown loaches are fat, happy, and beggy! Just wanted to let you guys know that the new clowns I recently received from a fellow LOLer are doing well.

Hi Icewall,

Glad to hear the clowns are doing well. I knew they would be!
I'm also happy that you've found the source of your black spots.

Take care.

[Tinman]

Very intresting. I have been experimenting with salt more myself convinced after your success' . I also pre filter with carbon and still have my issues with blackspot as well....very intresting indeed....

[Icewall42]

Yes, the salt was successful, but it wasn't a permanent solution as I hoped. It seems it purged the spots from the slime coat, but it only treated the symptom, and not the cause. It's certianly worth some study. But if you still have the spots, take out all your carbon and see if that helps. If it does, we might be on to something.

Also, I once thought carbon was carbon no matter how it came, but I've used Black Diamond for years without these spots. I recently changed to another brand/style of aquarium carbon that I can't name off the top of my head, but maybe this also plays a part?

[chefkeith]

That's a great observation. I think that almost fingers the cause. Granular Activated Carbon (GAC) can change the chemical profile of the water rapidly.
I've used carbon occasionally. I do have Black Diamond carbon on hand and have used it for the past couple of years. Before that, I usually used the more expensive stuff, coconut carbon I think. I was having black spot problems much more frequently back then, and obviosly I used it all up.

Last week, a few of my clowns had a small outbreak of black spots after I topped off the tanks with tap water. Luckily, the spots are fading away fast. It seems if I do anything other than a drip water change, my clowns will get some new black spots.

So my thought is that this new carbon you got is working better than the Black Diamond stuff.

To the big question- What material are we removing? GAC can remove trace elements and other organic materials that can cause color and odors. GAC, like doing water changes, must be removing something essential to our fish. It might be an element or maybe it's even something that the fish produce.

Here's a link about some of the things that GAC can remove.
http://www.thekrib.com/Plants/Fertilize ... arbon.html


PS-
That's great news about the adopted clowns.

[Icewall42]

The Black Diamond was working well for a while. I think this new stuff is causing the problem. Anyhow, it's worth looking into. You can thank my mother for coming up with this possible cause

[chefkeith]

So you think the activated carbon is leaching something into the water?
You may really be on to something. I looked more into it. Activated Carbon is usually inert, but if it was activated chemically it may leach zinc trace residues.

Maybe Zinc is the culprit.
Every article I've read about zinc makes it sound plausable.
http://en.wikipedia.org/wiki/Zinc
http://www.i2k.com/~suzanne/Page%20103-Zinc.pdf

I started using brass pipe fittings for my python hose many moons ago when the black spots first started. I stopped using my python hose for awhile, but I used it last week when I topped off the tanks. Brass is made of copper and zinc.

One way to test this is to put some pennies in the .......nevermind. Not worth the risk.

[Icewall42]

Yes, I think I agree. The carbon must be the thing that's leeching stuff into the water. Maybe something in this city water activated the inert chemicals? And maybe they weren't activated back home, where a different water supply was available?

Zinc does sound very likely. I was reading what you posted, and it seems that zinc is a major component of pigmentation... could that be while the spots are showing up? That might be a stretch. Even if it isn't zince (though it sounds likely, based on what you said), it is almost certainly something else in the carbon.