Guppy either "Stands up" or sits at bottom

[Major Risk]

Hi,
My Male guppy is ill, he was just sitting at the bottom of the tank. I then "quarantined" him in a breeder box. Here he either attempts to swim or sits at the bottom or Stands up on his tail. (see pictures).
I have had him for around 2.5 years and the tank has been cycled for around 3 years now. He just seems exhausted and is eating little to nothing. His Caudal fin is slightly split into 3 different parts. (he was like this before and had no visible problems)

Tank is 15 US gal/ 58 Litres.
Filter is Fluval U1 (65 gph).
Planted Tank
pH is 6.8. Temp is 28'C.
Tankmates are 5 neon and 5 glowlight terats (all under 1 inch), 9 other male guppies (of which 3 are under 1 inch and 6 around 1 inch.)
(Works out to about 3 inches overstocked )
I have just done a 80% water change.
I do a 80% water change biweekly in this tank, but sometimes do 50% every now and again, to supplement the 80% which happens every other week.

I have recently added some bogwood, to the tank, the exact same type I added to my other tank and the fish are doing fine in their.

I don't think the ammonia and nitrates/nitrites would be a problem because all the other fish are happy and it is a planted tank with duckweed with next to no algae and has been established for years.

Does anyone have any clue as to why he is ill? Is it just old age?

 

[lornajane89]

Livebearers generally dont live too long, ive not had guppys last nearly that long. Did u have it from fry? If hes eating you could try peas incase its swimbladder but sounds like hes dyin. Sorry mate

 

[scunnypaxo]

Lack of oxygen into tank maybe? Is the filter fully submerged? If it is it shouldn't be. It should be located so that the water coming back out breaks the surface of the water.

 

[Major Risk]

Filter is sufficiently disturbing water, it has a venturi system that diffuses oxygen somewhat into the water, and yes I have had him from fry.

Could it be fin rot? or fin nipping? If you look at his caudal fin?
I going to feed him a pea, to see if it is swimbladder, any suggestions on how to do this...?

And thanks guys.

 

[lornajane89]

Boil it and mush it up a bit then try. If hes sick he might not be interested tho.

 

[lornajane89]

Fin rot is bacterial water issue. Im struggling with FR with my swordtails. I dosed the tank with pima fix and melafix for a week with no results. Now im back to 50%pwcs every few days and still nothins improving.

 

[Major Risk]

Hmmm...no treatments were working, he ate peas with no effect. Seems he was in pain, and was unhappy, so I euthanized him with clove oil....
Just not my luck this week

 

[lornajane89]

sorry bud, once they get like that its pretty much too late, so far ive diagnosed a couple of deadly illnesses with my 2 tanks and every one regardless of treatment and determination have died or been euthanised as they just got worse.

hopefully its nothing to worry about and no more of your fish will be affected. at the minute i keep on treating with each diagnosis i get and i just feel like im delaying the inevitable and waiting for my fish to die so i can bleach the tank and start over.

 

[scunnypaxo]

I know you probably did do this but for people who maybe don't know. Did you take the carbon out of the filter? Treatments don't work with it still in.

 

[Major Risk]

Yeah, took carbon out. Think his time had come, luckily all other fish are fully healthy/ unaffected , starting to think it was old age. Anyway thanks guys for your input!