Ich does not persist in tanks unless you feed it new fish before it's run its cycle. In the wild, it hops from host to host, never building up numbers because it finds its hosts in large flowing environments. It never builds up the populations trapped in the walls of a tank. It's an anecdote, but I have never had a recurrence without an introduction of the parasite on new fish.
Malachite is a naturally occurring mineral, for the anti chemical crowd. It's connected to copper, which is why it is dodgy for invertebrates. Overdosing is dangerous. Copper is a deadly poison to Ich, and in the past, chelated copper meds were a big thing. Once we understood what they did to fish and fishtanks, they came off the market quickly. I've used malachite green in dye form for years now, and it hasn't killed snails, or even hydra. So it isn't as toxic in my estimation as copper, or salt (which is harder to remove and a longterm issue for many fish). Most of my fish are rainforest species, coming from temps between 20-23c, and driving temps to 27 or higher for a couple of weeks would radically shorten their lives.
As well, I have seen Ich survive heat treatment, so there are heat resistant versions. Evolution moves fast on the crowded fish farms. I go with the meds, an unpopular choice to many, and don't really worry about Ich. Tropical fish getting chilled and being open to outbreaks is just a fact of life when half the year here is quite cold. I've visited major importing facilities for Asian fish and the tanks were all on central filtration with no UV - they had Ich running and counted on high turnover before the outbreaks showed. Fish arrived and were immediately sold. 50 connected 40 gallons per bank, in row after row after row doesn't need a dormant parasite.
I've had ten year stretches without seeing Ich in my tanks, and then had it show 3 times in 3 purchases (all quarantined and rapidly dealt with). It's very nice to argue a holistic, water change only approach, but you can rest assured that the ways most fish are produced as commodities, shipped, handled and distributed is not natural. Only natural habitats produce 'naturally raised' fish.
BTW - it takes 3 weeks to be sure you've cleared Ich. There are species that resist it, and species that are Ich magnets.
Malachite is a naturally occurring mineral, for the anti chemical crowd. It's connected to copper, which is why it is dodgy for invertebrates. Overdosing is dangerous. Copper is a deadly poison to Ich, and in the past, chelated copper meds were a big thing. Once we understood what they did to fish and fishtanks, they came off the market quickly. I've used malachite green in dye form for years now, and it hasn't killed snails, or even hydra. So it isn't as toxic in my estimation as copper, or salt (which is harder to remove and a longterm issue for many fish). Most of my fish are rainforest species, coming from temps between 20-23c, and driving temps to 27 or higher for a couple of weeks would radically shorten their lives.
As well, I have seen Ich survive heat treatment, so there are heat resistant versions. Evolution moves fast on the crowded fish farms. I go with the meds, an unpopular choice to many, and don't really worry about Ich. Tropical fish getting chilled and being open to outbreaks is just a fact of life when half the year here is quite cold. I've visited major importing facilities for Asian fish and the tanks were all on central filtration with no UV - they had Ich running and counted on high turnover before the outbreaks showed. Fish arrived and were immediately sold. 50 connected 40 gallons per bank, in row after row after row doesn't need a dormant parasite.
I've had ten year stretches without seeing Ich in my tanks, and then had it show 3 times in 3 purchases (all quarantined and rapidly dealt with). It's very nice to argue a holistic, water change only approach, but you can rest assured that the ways most fish are produced as commodities, shipped, handled and distributed is not natural. Only natural habitats produce 'naturally raised' fish.
BTW - it takes 3 weeks to be sure you've cleared Ich. There are species that resist it, and species that are Ich magnets.
