egg cleaning for corydoras

[Sgooosh]

Hello, I am wondering if I can use Seachem Paraguard for the disinfection of corydora eggs so I can hatch them, or do I have to use Metheleyne Blue?

 

[GaryE]

Methelyne blue is mildly antiseptic in the dose you'd use for eggs, but eggs that are unfertilized turn blue in it. That lets the breeder remove 'bad' eggs before they cause fungus to spread to the good ones. You don't use it to disinfect as much as to support your hands on efforts to protect the eggs.
Clean water with oxygen providing and dirt removing movement to it will take care of fertilized eggs.
Paraguard is malachite green based, and that dye works differently. It's for killing freeswimming parasites, but not for protecting eggs. I would not let it near Cory eggs as it would be in the water after hatching. I'd argue it's a great treatment for Ich, but it's not an additive for breeding. It's too strong.

 

[ghyti]

You can use Jungle Fungus Cure tabs. One half a tab per gallon works good. It does not harm the fry like Methelyne blue does.

 

[GaryE]

You can use Jungle Fungus Cure tabs. One half a tab per gallon works good. It does not harm the fry like Methelyne blue does.

I have never seen evidence methelyne blue harms fry. If you do the accompanying water changes right, it's gone by the time the fry hatch anyway.There is evidence nitrofurazone, the med in Fungus Cure, is carcinogenic and mutagenic. Meth blue has limited uses in human medicine, but nitrofurazone is out because of that.

You do a light water colouring with meth blue, remove blue eggs, water change and keep things oxygenated.

 

[ghyti]

No need to do water changes on eggs. Only reason to do water changes on eggs is to get the methelyne blue out before the fry hatch. I let fry hatch in the Fungus clear then start water changes. Have never seen any harm to fry even after 1- 2 day exposure. I've never seen any evidence of harm either but I have seen plenty posts warning about getting the methelyne blue out before they hatch. If it doesn't cause harm why take it out?

 

[GaryE]

No need to do water changes on eggs. Only reason to do water changes on eggs is to get the methelyne blue out before the fry hatch. I let fry hatch in the Fungus clear then start water changes. Have never seen any harm to fry even after 1- 2 day exposure. I've never seen any evidence of harm either but I have seen plenty posts warning about getting the methelyne blue out before they hatch. If it doesn't cause harm why take it out?

it has served its purpose, so why leave it in? I've used it a lot for killie eggs, and if the fry hatch in it, there is no harm. But it isn't necessary for it to be there, and my killies incubate mostly for 14 to 18 days. In an egg container, I put the blade of a knife I've dipped in the solution and swirl it. I use that little. It's there as a dye to tell me which eggs are bad.
I have never had to use meds on Cory eggs. The incubation is fast enough that a little eyeballing of the eggs does it.

We're talking at cross purposes. I described how to use methelyne blue, and for it, you need water changes to do it right.

In previous times, people used a lot of acriflavene, which like your Jungle med is now a known carcinogen and mutagen. I never heard anyone talk about damage to fry from it, and it didn't seem to damage fishkeepers. I used it for a few years til it came off the market. Fish meds are an unregulated, wild west world, so some sketchy stuff is still sold in some places. How much exposure we need, or fish need to be a problem is always a question. I prefer to err on the side of caution.