Fish have an insulation, a slime/moisture that coats their bodies and protects them from both iffy water acidity and chance encounters with parasites; it also may limit bleeding in injury and promote healing of minor scrapes.
Things that diminish the slime coat: the alkalinity of your water being out of bounds (the range should be 7.9-9.0 on the dkh scale, and if you aren't testing your alkalinity weekly, you should be. Daily, when just starting your fish out in your tanks.) Note also that if you can't keep your alkalinity up your magnesium is also too low: set that at 1350 and you won't have to go on adding buffer (which is how you raise alkalinity.) Kent makes a good buffer. Salifert makes a good numerical alk test. And one for magnesium. Tests are pricey, but so are fish.
The other thing that diminishes the slime coat is what humans would call physical or emotional stress. Overcrowding, mostly, and fear. Pain. Sickness. Bad diet. Or actual wounds. Put too many fish in a tank and everybody's slime coat goes downhill.
Some people mistakenly think that stress causes ich. It doesn't. Ich is like fleas: it infests fish. It's an animal, and the only thing that produces it is another ich. HOWEVER: stress thins the slime coat, right? And the slime coat of a healthy fish MAY turn away a parasite. THe poor stressed fish is more vulnerable to such attacks. Certain fish that produce so much slime they're like handling Jell-o can defeat ich....but even they can succumb if just one ich-swimmer gets through that coat.
This is why we say watch your alkalinity: keep it in the Zone...and don't overcrowd. If fish are stressing out, bad things happen. And if you don't qt a fish, and put one in that's got the parasite---the odds are with the parasite: new, anxious, scared---and infected fish, or fighting and chasing---there go the odds.
THere are products that increase slime coat but they're meant to help an ailing fish: they're not for general use.
Keep everybody healthy, your water proper, and give them plenty of room and cover, and your fish will have a good natural protection against problems.
Things that diminish the slime coat: the alkalinity of your water being out of bounds (the range should be 7.9-9.0 on the dkh scale, and if you aren't testing your alkalinity weekly, you should be. Daily, when just starting your fish out in your tanks.) Note also that if you can't keep your alkalinity up your magnesium is also too low: set that at 1350 and you won't have to go on adding buffer (which is how you raise alkalinity.) Kent makes a good buffer. Salifert makes a good numerical alk test. And one for magnesium. Tests are pricey, but so are fish.
The other thing that diminishes the slime coat is what humans would call physical or emotional stress. Overcrowding, mostly, and fear. Pain. Sickness. Bad diet. Or actual wounds. Put too many fish in a tank and everybody's slime coat goes downhill.
Some people mistakenly think that stress causes ich. It doesn't. Ich is like fleas: it infests fish. It's an animal, and the only thing that produces it is another ich. HOWEVER: stress thins the slime coat, right? And the slime coat of a healthy fish MAY turn away a parasite. THe poor stressed fish is more vulnerable to such attacks. Certain fish that produce so much slime they're like handling Jell-o can defeat ich....but even they can succumb if just one ich-swimmer gets through that coat.
This is why we say watch your alkalinity: keep it in the Zone...and don't overcrowd. If fish are stressing out, bad things happen. And if you don't qt a fish, and put one in that's got the parasite---the odds are with the parasite: new, anxious, scared---and infected fish, or fighting and chasing---there go the odds.
THere are products that increase slime coat but they're meant to help an ailing fish: they're not for general use.
Keep everybody healthy, your water proper, and give them plenty of room and cover, and your fish will have a good natural protection against problems.
