protozoans and treatment

Fishfinder · Jul 16, 2017

I know that the go to for protozoan infestations is either copper or CP. Why cant Malachite Green be used? I see on Mardel's website they say it can be used to treat parasitic and protozoan infections. Why is this not a good treatment?

melypr1985 · Jul 16, 2017

Most products now a days claim to treat for ich and cure it. It's pretty much never true for actually curing it, but some will help boost the immune system to help the fish live with it. Malachite Green is good for injuries and should be done in a bath. It can be a bit harsher on the fish than Methyline Blue so we almost always recommend the MB.

Fishfinder · Jul 16, 2017

Will it remove the ick from the fish if put in a bath?

If you did a couple baths and transferred to clean systems after each bath, I'm curious if that would be effective?

4FordFamily · Jul 16, 2017

Fishfinder said:
Will it remove the ick from the fish if put in a bath?

If you did a couple baths and transferred to clean systems after each bath, I'm curious if that would be effective?

Not marginally effective, no. Unfortunately.

Temporary relief, yes

Fishfinder · Jul 16, 2017

Ok, thanks for the help

Humblefish · Jul 16, 2017

I actually did some pretty extensive experimentation with Malachite Green when I lived in the UK, since it is a popular med there.

I used it (for 30 days) to treat fish with FW Ich, Crypto and Amyloodinium. While conditions did improve somewhat during treatment, the white spots kept coming back throughout which proved to me either: a) MG is not capable of eradicating ALL theronts/dinospores b) I wasn't using a strong enough concentration of MG (but I wasn't too far from the lethal dosage). Most of the fish with velvet eventually died, but I did save all the fish with FW & Marine Ich by treating for 30 days with Cupramine. I was using a colorimeter 2x daily to measure malachite green concentration in the water. So, this is why I am so confident that it's not 100% effective against ectoparasites.

There are many studies which talk about Malachite Green (and Methylene Blue) being used as a antimicrobial, and I have had some success using both to treat bacterial infections. I plan on experimenting with both soon for that purpose only. But not as an antiparasitic.