E.M. Tablets good for coral health?

[smarsh]

I have been in this hobby for 16+ years. During highschool I worked with a aquarium servicing company and when a client had red slime algae we used API E.M. tabs to treat the problem. I still use this method today to treat any out breaks in my DT. It has been a year since I had any red slime. So I had a little patch start last week and put two tablets in there.

 

This week my zoas and SPS look like they are on steroids and a few zoa colonies that have always been sick on and off are coming back. My nuc green palys made 4 babies in a week and have doubled in size. The polyp extension on my SPS is ridiculous! I was just wondering if the treatment had anything to do with this? It is eurtyromycin (antibiotic) so it make sense that it works on cyano. It was like a B12 shot for my corals.

[Diatome]

Erythromycin is hard on nitrifying bacteria. Here is my theory; you treated with this and you lost certain kids of bacteria so now your water is dirtier. Lets say your water was pristine before and zoas were getting by and leathe rcorals were just plain unhappy. Now the water is dirtier and the zoas are happy. Problem is, this can throw things off and the corals that like cleaner water, such as acros, may start to be unhappy. The bacteria bounce back but the tank is a litle out of whack.

 

Where is Mr. Fosi when you need him?

[smarsh]

Paging Mr. Fosi on this one!

[Mr. Fosi]

Maybe the tablets are doing this and maybe they aren't... It's an unreplicated event.

 

Erythromycin is hard on nitrifying bacteria.

 

Do you have a citation for that?

 

Here is my hypothesis...

 

FTFY and not a bad hypothesis but I wonder what mass of the antibiotic is in each of those tablets. If it is only 10 mg or so, you end up with an approximate in-tank concentration of 0.26 mg/L (ppm) which is really low. If it is 250 mg, then it's 6.61 ppm, which is higher, but still not very high.

 

Bacteriocidal activity in erythromycin is only hypothesized and the best evidence comes from when it is used in high concentrations. Because the concentration is so small, I am not inclined to think that the antibiotic is causing bacterial death. Rather, the antibiotic has probably slowed the growth and activity of a range of the microbes in the tank.

 

I suspect that, if this antibiotic is fueling this effect, it is because certain bacteria who have been acting as mild pathogens have been slowed down. Once they are slowed down, assuming grazer activity hasn't also been inhibited, they will be reduced in number as they are consumed and are unable to reproduce at their "regular" rate.

[smarsh]

Thanks Fosi. I will check what mg the tablets are when I get home. They definitely had some effect because I did nothing but normal Ca, Alk and Mag dosing over this time. No water change or media change at all. I have had SPS for about a year and never really had extreme polyp extension, stuff grows and is bright but had minimal PE except for at night. I thought this was due to my tank running at about 83F during peak times. i was amazed this week when I came home and some acro polyps were so extended they were clear in appearence and activley closing and opening catching plankton, its like the polyps have doubled in size, even monti cap tiny polyps are bigger then ever.

 

Thanks for the hypothesis from you and Diatome, like you said it is a one time thing so too much is left unanswered to conclude if the EM tabs had anything to do with the success.