Bullying Pleco!

[Rory the cat]

Posting this on behalf of my mother in law.

She has kept a common plec in the same tank for about 8 years now, he's not all that big (about 6 - 8 inches). He's always been fine with all his varying tankmates.

For the past year it's been just him and one small Albino Cory. the Albino then passed on and she allowed the plec to be on his own for about 3 months - in that time he seemed quite unhappy.

So, 6 weeks ago she planted the tank up quite heavily and bought 6 small angels and 2 large (2 - 3 inch) peppered corys.

Pleco won't leave them alone - he picks on all the fish mercilessly, chases them, rams into them and generally won't leave them be.

The Angels have been dying off at about one a week - there are 2 left and both have bad ICH and are gasping heavily. The Corys have now also started with ICH and are hiding constantly and not feeding - afraid of Pleco.

What can she do? She is considering a tank divider (I am not sure how big her tank is - I guess 25 - 30 gal) between Plec and the other for a month or so. I have suggested taking plec out, rearranging the tank and then adding him back and seeing how she gets on (I've seen this recomended on this board before for bullying fish).

Please does anyone have any ideas? She's been keeping fish over 20 years, but this has her stumped.

 

[ryan]

It isn't uncommon for larger Plecs like Common and Gibbiceps to become aggressive with age. My last Gibbiceps reached about 8" and started to turn nasty and tried to suck on the sides of larger fish and chased all other bottom dwellers. However, I shouldn't think he is stressing them and causing white spot, have you checked the water parameters?

 

[Rory the cat]

I checked last night and she has 0 nitrIte & ammonia, though her nitrAte is very high (about 100 or so). I have advised her to switch to stress coat to condition water, as I have done as it seems to bring the nitrAte in the local tap water down to next to nothing.

 

[ryan]

I checked last night and she has 0 nitrIte & ammonia, though her nitrAte is very high (about 100 or so). I have advised her to switch to stress coat to condition water, as I have done as it seems to bring the nitrAte in the local tap water down to next to nothing.

Well theres the cause of the disease, try to do 10-20% daily water changes until the parameters are back to normal and treat the ich, if you are in the UK I have found that Protozin is the best product to use.

 

[EX-AmP]

plecos are territorial especially against other plecos. if hes been alive that long he probably feels that its his tank and he must defend it