Fish around surface

[Jamesthecat]

Hi all

Just after a bit of advice - this isn’t my first tank but I’m by no means an expert.

My new 5 ft tank ( pictured ) has a fairly low stock level, ammonia, nitrate and nitrite are all 0. Nothing seems out of the ordinary but there’s about 5 or 6 of the 40 or so fish constantly at the top of the aquarium by the surface in a specific corner. Its an empty corner - no heater or filter intake / outflow.
I wouldn’t say there ’gasping’ just constantly loitering there - there eating ok as well.
The other 40 odd fish are quite happy in a shoal or nibbling here and there.

Any ideas?

 

[itiwhetu]

What species are they

 

[itiwhetu]

It looks like a water property issue. Soft water fish in hard water, or something similar

 

[Jamesthecat]

Various Mbuna Malawi cichlids, seems to be a group of 4 Pseudotropheus cobalt blue

 

[Jamesthecat]

It looks like a water property issue. Soft water fish in hard water, or something similar

GH is 4 KH is 6 so its on the low end of whats ok , could it be the amount of dissolved oxygen in the water?

 

[itiwhetu]

What is the pH of your tank

 

[Jamesthecat]

What is the pH of your tank

8.2

 

[itiwhetu]

How long have these fish been in this tank, and what was the water like from where they came from

 

[Jamesthecat]

Ok so they were in my 3 foot tank. I bought the 5 footer, set it up and moved over some filter media into the Eheim external. Cycled the 5 footer then slowly moved them all over.

Theyve all been in the 5ft tank for around 3 weeks now. The tank was cycling for about 2 weeks with the other tanks water and media before i added them

 

[itiwhetu]

Are you sure that the ammonia level is constantly at zero and not fluctuating. They look like they are not enjoying this tank for some reason

 

[Jamesthecat]

Mmmm, Ive just stuck my temperature probe in some iced water to see if its accurate and it looks like its 2.5 - 3 degrees C off. Would the elevated temp be making them gasp?

 

[Jamesthecat]

Yeah - tbh i wa a bit nervous about having a bigger tank so ive been testing every day and logging in Aquarimate. The readings have been more stable than the other tank.

 

[itiwhetu]

So how warm is the tank, I keep these guys at around 24 degrees

 

[itiwhetu]

The lower the temperature the more oxygen in the water.

 

[Jamesthecat]

The STC controller was at just over 25 so if its 2.5 out then it must be hitting over 27