poorly harlequin and other travails

[Catfish586]

Hi. I've had a couple of unexplained deaths in the last few weeks and now a harlequin raspbora looks off colour. It looks paler than it should and seems to be hovering near the top a lot. I've also got a cardinal tetra which looks massive - could be egg-laden (otherwise seems OK) but I'm not sure. I have tried Interpret anti internal bacteria medicine this week, but no visible improvement. I've changed 20% of the water and the levels are all fine. We're about to go away for a week so I'm worried about the fish, especially the harlequin, In the meantime. Should I do a huge ie 75% water change to buy some time and see if that sorts it?

 

[Catfish586]

Update. The fish was on the floor of the tank and clearly struggling so I've had to euthanise, unfortunately. The other Rasboras doesn't look good either: seems to be struggling for breath and looks like something is untoward with his body. It looks red/inflamed. Is this a parasite problem?

 

[Slaphppy7]

@Colin_T , have a look, please

How long has this tank been set up? How long have you had the fish?

 

[hansgruber7]

You should test your water for ammonia, nitrite, nitrates. We would need more information about your set-up to be able to help you. It sounds to me like you may have a water quality issue. It could also be a parasite. Have you introduced anything new recently?

 

[Catfish586]

It's a 55L tank which has been set up for two years with very few problems. I fairly recently introduced four head and tail light tetras, of which one didn't look right from the off and didnt survive. A few weeks ago a neighbour gave me a cardinal tetra. All the levels are in the OK bracket with the testing kit. I've got some parasite treatment so am thinking big water change and then add the treatment? What do you think? Many thanks

 

[Bruce Leyland-Jones]

...What do you think? Many thanks

I think you need to give us accurate water parameters, so that we know what we're working with.
Always happy to help, but we do need some clear info, otherwise, we're just guessing...and that rarely works out well for anyone.

It's rarely a good idea to simply lob random medications into a tank, before you know what it is you're treating.
We know it's a 55l tank, but not the dimensions. Nor do we know how many fish you have in there and of what type.

 

[Catfish586]

Am with you. It's a 55l AquaNano 40cm cube. I've got one remaining rasbora Three black neon tetras, seven cardinal tetras and three head and tail light tetras, plus a bristle nose plec. I'll do the parameters in the morning as it's in the child's bedroom and he's asleep (or rather, should be). I do know the PH is 6.8. and because it's so hot I'm struggling to keep the temperature down. t's been higher than normal and can get up to 30 purely from daylight.

 

[Bruce Leyland-Jones]

Am with you. It's a 55l AquaNano 40cm cube. I've got one remaining rasbora Three black neon tetras, seven cardinal tetras and three head and tail light tetras, plus a bristle nose plec. I'll do the parameters in the morning as it's in the child's bedroom and he's asleep (or rather, should be). I do know the PH is 6.8. and because it's so hot I'm struggling to keep the temperature down. t's been higher than normal and can get up to 30 purely from daylight.

That helps.

You've got room for 15" of fish, assuming all is going well and the fish share the same parameters. (This is just a loose 'ball-park' figure, from the Olden Times, using 1" of fish per 1 square inch of tank surface area and doesn't take into account the details such as swimming space for more active fish, or the needs of some fish to be able to shoal with reasonably large numbers of their own kind).
You've got about 1.5+3+7+5+4.5=21" of fish, suggesting overcrowding.

All three tetras need to be in shoals of at least 6 and preferably around 10, in order to be stress-free. (Harlequins need to be in shoals of at least 8 to thrive)...this suggests a potential for stress.

 

[Catfish586]

I think we're probably about 14" plus the plec, which is about 3 inches now, so yes, point taken. We started off with (from memory) seven rasboras, seven cardinals and what was a baby plec, but things have taken a different course as we lost a few rasbors to jumping early on (before I finally managed to stop them leaping out) and the boy decided he wanted different tetras. We were told they'd happily shoal together, but I can see the potential problems especially for the poor rasbora now he's the only one left.

 

[Catfish586]

Parameters are (with water due for weekly change)
PH 6.8
Carbonate hardness 10
General hardness 7
Nitrate 10
Nitrite 0

Fish seems stable/same

 

[Colin_T]

ammonia level?

need more pictures of all the fish, please make sure they are clear and in focus.

 

[itiwhetu]

As the temperature rises the oxygen level in the tank decreases. Ways to combat this is more aeration or more plants. Increasing the filter flow will also help. But all said and done 30 degrees is a little warm for the Black Neons and Harlequins

 

[Bruce Leyland-Jones]

I think we're probably about 14" plus the plec, which is about 3 inches now, so yes, point taken.

Don't forget, these fish are supposed to grow and, if properly cared for, can keep on growing for a while yet.

...the boy decided he wanted different tetras.

Regardless of how old your boy is, you need to do some proper research on your fish before you buy, rather than depend upon what sounds to be very dodgy sales-related advice. Such research can be a joint project and should begin to instil into the lad the importance of looking after other living creatures.
For yourself (and maybe the lad, who knows?), I'd recommend this website; Seriously Fish.

 

[Catfish586]

Thanks for all this. We did do a lot of research before getting the tank but it's an ongoing learning project, clearly. I've also realised that my 5 in 1 test kit doesn't include ammonia, so will get test strips today. The tank has always been well planted although I've never had much luck with them apart from one particularly plant, which seems to grow with ease. I had tropicals in my own youth but a lot has changed advanced and I clearly need to read more. It feels cooler today so hopefully will keep the temperature down. This has only been an issue during the heatwave

 

[Bruce Leyland-Jones]

Thanks for all this. We did do a lot of research before getting the tank but it's an ongoing learning project, clearly. I've also realised that my 5 in 1 test kit doesn't include ammonia, so will get test strips today.

Test strips are okay-ish, but fall into the cheap and not-so cheerful bracket.
I'd always recommend getting the liquid tests, as they seem to offer more precise and consistent results.

I've 'only' been away from the hobby for 13 years, but I was very surprised by the changes in so short a time.
Fortunately, there's a lot more excellent information available and good stuff to buy, thanks to Thinternet.
Unfortunately, for every piece of good info, there are lots and lots of bad.