Is Maracyn safe for reef tanks

[bspoon]

I have green Star polyps and Kenyan trees and mushroom corals. My few fish have just developed “lateral line” fungus. The aquarium store owner suggested I treat the fish with Maracyn. The box says “safe for invertebrates”. Is it safe to use in my tank? My tank cleaner guy said not to use it

 

[Jay Hemdal Verified Community Expert]

Welcome to Reef2Reef!

I've used Erythromycin (Maracyn 1) in reef tanks to control cyanobacteria, at a dose of 10 mg/l. I didn't see any issues with soft corals or LPS, but the tanks did not have any SPS in them. Trouble is, I have no way to tell you how that compares to the dose on the box of Maracyn 1. I found a web site that says Maracyn 1 tablets contain 200 mg of erythromycin. These will dose 10 gallons of water, so 20 mg/gallon. This is less than the dose I used for cyanobacteria.

That said - in looking at the picture, I see a fish that is producing mucus, but I can't say that it is infected, and then, if it is infected, it is most likely with gram negative bacteria, and I always thought Maracyn was more effective against gram positive (usually internal) bacteria.

Conclusion? I probably would not dose your tank....

Jay

 

[bspoon]

What would you recommend for a gram negative bacteria?

 

[Jay Hemdal Verified Community Expert]

Choosing a antibiotic - aside from gram negative versus gram positive, is pretty much just a guess. People tend to side towards one over another due to their past experiences, but in the end, without a sensitivity test, everyone is just guessing. That said, my favorite is Neoplex, followed by Kanaplex. If your local stores don't carry those, then Maracyn 2 would be my third choice. None of these should be dosed in a reff tank though.

Jay

 

[bspoon]

Choosing a antibiotic - aside from gram negative versus gram positive, is pretty much just a guess. People tend to side towards one over another due to their past experiences, but in the end, without a sensitivity test, everyone is just guessing. That said, my favorite is Neoplex, followed by Kanaplex. If your local stores don't carry those, then Maracyn 2 would be my third choice. None of these should be dosed in a reff tank though.

Jay

My aquarium cleaner guy said to always choose Coral over fish....is that the only solution to sick fish in a reef tank?

 

[Jay Hemdal Verified Community Expert]

There are “reef safe” medications out there, but most of them are “bacteria safe” as well. Most of them are snake oil at worst, and mild tonics at best. In this case, if you can’t move the fish to a treatment tank, I would agree to choose corals over fish. This still looks like mucus to me - is it getting worse?
What other fish have it?
Jay