Concerned about fish symptoms

[nphsmith]

I am, I think, reaching the end of our nitrogen cycle (With fish in tank). Ammonia has been 0-ish for over a week, and while Nitrites were very high for a while, they have now diminished to 0.25ppm. Nitrates are still low.

Noticed yesterday that out 2 platies are 'gasping' at the surface, and I think have redder gills. I did a 50% water change and the gasping behaviour immediately diminished, and was absent this morning. We didn't feed them as usual this morning.

This evening, both our platies are gasping, as is one of the Danios. Gills still look red (Though our 2 Barbs and 2 cories seem fine).

Is it possible that previous high Nitrite levels have damaged them and symptoms are only showing now? Or is it more likely to be Oxygen issues? I've twisted the filter outlet so it is pointing up and therefore increasing oxygen flow. I'm also planning on leaving lights on overnight so plants will create more O2.

Anything else I should be doing? anything else it could be?

Many thanks in advance.

 

[BigJim]

If the PWC decreased the behavior, I'm inclined to believe that you don't have enough oxygen in the tank. Ammonia burns the gills of the fish, making them less efficient at getting oxygen out of the water.

You did the right thing with aiming the filter return to agitate the surface of the water more. I wouldn't leave the light on overnight. Plants need a rest period and the excess light will lead to algae issues. For emergency oxygenation you can add a few mL of hydrogen peroxide to the tank. It dissociates into water and oxygen when added to water.

 

[nphsmith]

Thanks, taht's helpful. I'll get some hydrogen peroxide tomorrow (night time now)

 

[nphsmith]

OK, this seems to have worked (Just moving the filter)- didn't mange to get out of work for hydrogen peroxide) - the fish are still alive, and no longer gasping. Their gills remain red - is this a permanent symptom of previous damage, or is it likely to mean there is still an issue?

As our nitrogen cycle seems pretty complete, I was planning on getting a (small) few more fish this weekend (Having resisted daughter and wife pressures for last few eeks ). Given that we had an Oxygen issue, is this premature?

 

[BigJim]

If you're not getting any ammonia readings, it may be natural coloration, it may be healing gills. I wouldn't worry about it if you keep the water pristine.

Is this your current stock list: 6 Danios, 2 small Corys, 2 platys, 3 harlequins in a 78L (~20g)? If so, I think you have a little room left. I'd start with adding some more cories. They do better in groups of five or more. You may be able to get a couple more harlequin rasboras in too. Otherwise, look at snails, shrimp, or other inverts.

 

[nphsmith]

Yes, that's correct re size and fish except I think the harlequins are in fact barbs (They have Zebra stripes rather than triangles)! Edit: I'm fairly sure they are tiger barbs.

I think you're suggesting we get some more 'cleaners'? Is that right? If so, it will please my wife who loves the corys. Are you also suggesting that we wouldn't fit many more in thereafter? Or just that cleaners should be the next step, and then maybe others in a few more weeks?

Many many thanks for your time.

 

[BigJim]

If they are in fact tiger barbs, they'll get too big and rowdy for your tank. Can you post a picture? There are five-band barbs that look like tigers with an extra stripe, but they stay small and rather docile.

Not really cleaners, but critters to fill the empty niches in your aquarium. Your current stock list does a good job of filling the water column. You have some room at the bottom of the tank. Cories would fill the bottom and the inverts help round out the ecosystem and add some points of interest to your tank.

 

[nphsmith]

You're right, I (now) think they are Pentazonas - they certainly do have 5 stripes (We have curve tank glass, so all pics come out blurry rubbish). All our fish were bought from local fish shop which seems to be run by a guy and his wife mainly because he doesn't have enough room at home to keep all the fish he wants to, so I'm mainly inclining to trust his advice (Over say the chain store guys).

My daughter is quite keen on....well, the wish list is enormous and unfeasible, but includes:

frogs
shrimp (Wife would like, I've explained would probably get eaten)
neon/cardinal tetra
Betta (Unusually, she's very keen on the females, more so than the males)
I quite like the ?Honey Gouramis, and the idea of having one somewhat larger fish (Eg a Betta or a red-tailed shark).

I don't think these really fit quite what you are suggesting?

 

[BigJim]

You could put a single female betta in the tank. Females do get just as large as the males. Bettas and gouramis don't mix well. Unfortunately you're getting close to maxing out your tank. A betta and a few cories would fill it.

 

[nphsmith]

Ok, we settled on a single male betta, put him in yesterday. I *then* read up about him, and realized that our tank was probably a bit cold for his needs (Heater at 24Celsius, hovered around 23.5 on the thermometers). I've bumped up the heat to 25.5, and the Platy I was first worrying about with O2 symptoms is gasping at the top again...so, should I lower temperature? How much does the Betta care?

 

[nphsmith]

In case anyone does a search, I continued to worry about Oxygen and eventually found a shop that stocked an Oxygen kit, which showed O2 down at 2ppm. I have now put in a seperate air pump/rock, which is creating much more disturbance on the surface. O2 is now at 5ppm, and the fish look much more comfortable - previously, they were hanging near the surface, which I thought was natural, but I now think they were staying near the Oxygen-rich surface.

Now that the pump is in, they are occupying the mid tank levels much more, which suggest the problem is solved.

 

[Viper]

Just FYI, higher water temperatures result in less oxygen in the water. Glad to hear things are going better now. You seem like a responsible fish-keeper who does their fair share of research before making decisions. You have a bright future in this hobby/lifestyle if you stick with it!