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Male Guppy Fin Rot for No Reason?

840 Views 9 Replies 7 Participants Last post by  wicca27
I've had a trio of albino red lace delta guppies for about a month now. About a week ago, all of my Pogostemon helferi melted, but the rest of my plants remained fine. No ammonia spike or anything, nothing was changed other than I started doing water changes with distilled water rather than tap.

Over the past 2 days, I've noticed the tail on the male guppy is getting frayed, like fin rot. Not white. It's clear.

I tested the ammonia again, still 0... I don't know why this would happen like a month after I got them. They've been fine so far.

Another thing I noticed which points to ammonia issues (which is impossible) is that one of the females goes up to the top and takes large gulps of air. I don't know why this is either because as I said, ammonia is 0.

I don't have anything to test nitrates/nitrites but the tank has been set up for two months. The plants are growing rapidly in it.

The three guppies are the only fish in the tank... What could be a possible cause of this? .-.

I've been doing weekly (sometimes every 3-5 days) water changes with distilled water. The tank was set up initially with tap water, which I use and have used for all fish tanks I've ever had since I was like born.
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I know RO water can strip your fish of minerals and trace elements due to the lack it the water and the RO process makes it effectively *thirsty* for them. Distilled water is also stripped of those elements and unless you are buffering the water before you put it in your tank to replace them to the approprate levels this may be causing you the issue. I had a major fish loss when i went to strait RO water on my 75 gallon now i do a mix of about 1-2 gallons tap per 5 gallons of water
Distilled water and RO water are very soft, and guppies (and most other livebearers) HATE soft water. Your guppy was likely weakened enough by the drop in TDS and hardness to pick up a fin rotting pathogen. Stop using distilled water in the water changes, or expect the guppies to start dropping like flies.
I agree with above.
Might also note that male guppies will nip the fin's of other male guppies to make themselves appear more handsome,and subdominant fish less handsome to the female's.
Put a bunch of male guppies together,and it don't take long to determine the dominant fish, for the other's fin's will be tattered.
Fancy overbred guppies just have no immune system left. They are not an easy fish to keep.
Yeah RO and especially distilled water is at least 6.0 ph. Guppies although very hardy, will have problem with that water. Mix half RO/Tap to produce close to 7.0 ph and that be better, pure tap is even better for guppies.
That's stupid but it make sense. I'll do a water change with tap. Thanks guys! :)
So what every came out with your fish?
I began doing water changes with tap water again and his tail repaired. It's much larger now, since they were young (but mature) when I got them, they still are growing. The colors are intensifying too and I have lots of baby guppies now. :D
there are more minerals in the tap. few fish need ro and when they do you have to remineralize
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