Common Pleco, Odd Behavior

HI everyone,

I'm new to the forum, so first of all hello! I'm a Bay Area resident who's had success with freshwater tanks for the last 12 years.

Right now I have a 65 gallon freshwater rig and a pleco (I'd say he's about 6" long) who's been acting odd for the last week or so. I got the pleco and an oscar, both juveniles, about 3 years ago, and while the oscar always chased the pleco around, he was always able to find refuge under his tree stump. They were both fine up until about 5 months ago when the oscar developed hole-in-head. Unfortunately nothing I did to remedy things worked and ended up losing the oscar.

Since my water was good I added a few goldfish to the tank and over time lowered the temp from 78 to 72 since goldfish don't need the water to be quite so warm. It took a long time, but the pleco finally figured out that the threat was gone and he was always out and about, day or night, hanging with the goldfish and having a good old time. He would zoom around the tank and play in the bubbles from the wands, and spend lots of time clinging to the glass.

A couple weeks ago I noticed that he'd become far less active, and was just sitting in the same spot. I though he'd died so I grabbed my net and went to scoop him out and he was all, "Hey, cut it out." and swam off. Assuming I went too cold I brought the temp up a bit to 74, but he's still pretty lazy.

The day before yesterday I found him on the bottom of the tank lying on his back and thought he was a goner, but once again I went in with the net and he flipped over and swam off.

I was bit overdue for a cleaning and water change so I pulled the fish, vacuumed, and did a 50% water change. The goldfish are pleased, but once again the pleco is just sitting in one spot. This morning woke to find him sort of up on one of the decorations, but he's been there all day and not moved at all, though I'm sure if I poke him he'll move.

Any ideas? The water's clean, the numbers are good, and the goldfish are as happy as can be.

Filtration note: from the time I bought the tank up until a couple weeks ago I used a Marineland Biowheel Emperor 400 filter. The first filter died so I got another one, but used the biowheels from the first filter. That one ended up dying as well so I switched to a Fluval AquaClear.

Perhaps changing the filter altogether has disrupted the biology enough to hurt the pleco?

Thanks for reading!

 

HI everyone,

I'm new to the forum, so first of all hello! I'm a Bay Area resident who's had success with freshwater tanks for the last 12 years.

Right now I have a 65 gallon freshwater rig and a pleco (I'd say he's about 6" long) who's been acting odd for the last week or so. I got the pleco and an oscar, both juveniles, about 3 years ago, and while the oscar always chased the pleco around, he was always able to find refuge under his tree stump. They were both fine up until about 5 months ago when the oscar developed hole-in-head. Unfortunately nothing I did to remedy things worked and ended up losing the oscar.

Since my water was good I added a few goldfish to the tank and over time lowered the temp from 78 to 72 since goldfish don't need the water to be quite so warm. It took a long time, but the pleco finally figured out that the threat was gone and he was always out and about, day or night, hanging with the goldfish and having a good old time. He would zoom around the tank and play in the bubbles from the wands, and spend lots of time clinging to the glass.

A couple weeks ago I noticed that he'd become far less active, and was just sitting in the same spot. I though he'd died so I grabbed my net and went to scoop him out and he was all, "Hey, cut it out." and swam off. Assuming I went too cold I brought the temp up a bit to 74, but he's still pretty lazy.

The day before yesterday I found him on the bottom of the tank lying on his back and thought he was a goner, but once again I went in with the net and he flipped over and swam off.

I was bit overdue for a cleaning and water change so I pulled the fish, vacuumed, and did a 50% water change. The goldfish are pleased, but once again the pleco is just sitting in one spot. This morning woke to find him sort of up on one of the decorations, but he's been there all day and not moved at all, though I'm sure if I poke him he'll move.

Any ideas? The water's clean, the numbers are good, and the goldfish are as happy as can be.

Filtration note: from the time I bought the tank up until a couple weeks ago I used a Marineland Biowheel Emperor 400 filter. The first filter died so I got another one, but used the biowheels from the first filter. That one ended up dying as well so I switched to a Fluval AquaClear.

Perhaps changing the filter altogether has disrupted the biology enough to hurt the pleco?

Thanks for reading!

HI Mystical Cat and welcome to the forum! Hope we can help.
The biology or actually the chemistry IS the numbers. What exactly are your numbers?
How long had you had the goldfish when he started acting different?
I doubt that switching out your filter caused a problem if you've got established gravel, sand, rocks and/or driftwood in the tank.
Do you have pictures of your Pleco? Closeups, top shots and a couple different angles help!

 

Apologies for the delay. We have an 11-month-old and she can be a handful.

Woke up yesterday morning to find that the pleco hadn't moved at all from the decoration, so I checked and he had indeed died. (insert heartfelt rendition of Taps here)

To answer your questions:

• Numbers: water is a bit on the hard side, pH is 7, nitrites and nitrates aren't even registering.
• The goldfish had been there for a few months, the odd behavior started a couple weeks ago.

I needed to buy some food so I went to my usual shop and chatted up the owner. He said it's not the water, it was likely either the temperature swing down and even though I brought it back up a bit he couldn't recover, or he simply got sick for some reason and just couldn't kick it. I have no live plants, though somehow I ended up with a couple snails at one point. I scooped them out and haven't seen any since.

 

What is your ammonia level?
Do you do water changes-how much/how often?
What kind of test strips/kit are you using?
Plecos can tolerate temps down to 72 without any issues. Goldfish produce huge quantities of waste. I suggest, to prevent further complications with your tank, that you obtain a good liquid test kit, like the API master test kit, that measures ammonia, nitrites and nitrates and do regular, weekly water changes. My guess is that because you were a "bit overdue" for tank maintenance, that your ammonia/nitrite and or nitrates were at toxic levels for the pleco and probably are what led to the Oscar's disease and death as well. I think the problems you are having are a result of inadequate tank maintenance. Set yourself a schedule. A water change and gravel vac for a 65 gallon tank shouldn't take more than 20 to 30 minutes total at most once a week.

 

Again, apologies for the delay. Human babies are much more needy than fish

Did an Ammonia test the other day, came in at 0 PPM. I'll keep checking, and definitely get back on my regular vac schedule.

Thanks!

 

Again, apologies for the delay. Human babies are much more needy than fish

Did an Ammonia test the other day, came in at 0 PPM. I'll keep checking, and definitely get back on my regular vac schedule.

Thanks!

You said your tank has been up for 2 or 3 years? It's probably not ammonia causing you problems, it's probably high nitrates. What are your nitrate levels? Older tanks that receive minimal water changes often develop high nitrate levels over time which is what or sounds like what your tank is doing. Fish die slowly from gradual nitrate buildup. Most sensitive fish first. The goldfish would probably be the last to die in a polluted tank. Might get a good test kit (not strips) and check those nitrates. It just takes some good water changes to get the nitrates down.