Meth Blue question

[David M]

Does anyone know how long meth blue remains active? The bottle (Kordon) doesn't say anything about re-dosing. The application is this, using it to prevent fungus on a nest. What I'm wondering is if after 3-4 days it's still doing it's job, or does it need to be supplemented? In this case I have had a nest in there for 3 days, I'm pulling it for hatching in a clean tank tonight. I have 2 more nests I want to move to the meth tank, don't know if the meth is still active or if I should empty the tank and start fresh. Trying to conserve water here, otherwise I'd just automatically change it

TIA, - D

 

[JHemdal]

David,

That's a good question, when I treat with methylene blue, I dose at 2 to 4 ppm (depending on how daring I feel) and then perform a 50% partial and a 50% re-dose every day or two. I'm not positive, but I think that meth. blue remains "bluer" in the water than its anti-fungal ability...that is, after a week or so, it still looks like a good blue dose, but it just doesn't seem to work as well.

One problem that I've had is that meth. blue seems to be inhibitory to nitrifying bacteria - you often see nitrite spikes after dosing a tank. Luckily nitrite is not too toxic in marine systems, because it is really difficult to run any sort of water test on a tank that is blue from dosing it (turns the nitrite test results sort of purple). One trick is to add a cup of tank water to be tested to a jar with fresh washed carbon - let it soak up the meth. blue, then filter it and use that to run your water tests.

Jay Hemdal

 

[David M]

You led straight into my next concern. Just how detrimental is MB to bio-filtration? For now I am using one tank to incubate and another to hatch & rear, afraid that I cannot dilute the meth fast enough with carbon & water changes to get my bio-filter going in the same tank. As for potency a FW breeder has suggested it weakens after 2-3 days, he re-doses at that point. For me I think I will just start fresh with each nest. I only keep the nest in the MB tank for 3 days anyway so my plan is a single dose and toss it after the three days. We'll see how it goes, so far results have been excellent producing the best hatch I've had since July 7th. Ever since then I have been losing nests if left with the parents so I started pulling early. Then I'd lose them to fungas The meth bath seems to do the trick