Advice - Something Going On In My Tank

[eduller]

I have a 54 gallon tank with the following stock:

• 10 harlequin rasboras
• 11 neon tetras
• 10 rummynose tetras
• 6 peppered cories
• 3 honey gourami

Every 2-3 days, the tetras and rasboras begin gulping rapidly with rapid gill movements. The gourami and cories seem unaffected. This would scream poor water quality or lack of oxygen to me, but I have been paranoidly testing twice a day, morning and night every day. Never even a hint of ammonia or nitrite, and nitrate is 10 or below. I took my time doing a very thorough fishless cycle, and I stocked the tank very gradually. I have a good filter flow and two large airstones going. I've taken a flashlight and inspected every last fish in the tank, and I don't see any signs of disease, ich, or anything else. The tank is fairly heavily planted and not overstocked. Doing a fairly large water change takes care of the problem immediately. I can actually see the fish returning to normal as the new water goes in. So if it were disease, I can't imagine fresh water would help. So it must be a water quality problem somehow? PH is around 7.4 always. The water is medium hardness, temp is 77 F maintained very evenly by an inline heater.
 
So the last 2 days, I have just been doing a 50% water change twice a day, which I know is just a band-aid and not fixing anything. I can't figure it out. I don't have a ton of algae - brown algae/diatoms on some of the swords but that's it. I don't believe I am overfeeding, and I vacuum the gravel well with every water change. There is very minimal if any plant debris laying around. The food is all eaten before it sits around more than a few minutes. I feed once per day - a couple of shrimp/veg pellets for the cories, small pinch of .5 mm pellets for the tetras and rasboras, and then I feed the gouramis 2-3 1.0 mm pellets each over in the corner because they don't like the rasbora frenzy, and I can feed them individually over there.
 
I do have a minor pond snail problem, but it's not like hundreds of them. Maybe a dozen or 2. And I pull out 2-3 per day to throw in the dwarf puffer tank. They are also about the size of a grain of rice each. Could the snail be throwing off the balance in the tank? Creating too much waste? I can get an assassin snail.
 
I have no idea how to troubleshoot this. More airstones? Should I get one of those long flexible airstone tubes and snake it through the center of the tank? It's a corner tank btw, so it's tall and deep.
 
I add PPS-Pro fertilizers daily as well as iron and liquid carbon every other day. My water conditioner is Prime. Sorry this is so long, but I wanted to be thorough!

 

[Chad]

It does sound like an oxygen issue the way you describe it. If it's a heavily planted the plants should be producing at least some  oxygen. Is the filter a canister or HOB filter?

 

[eduller]

It's a canister filter. Rena Filstar XP3 if that makes any difference. Should I add a spray bar or something?

I did just go out on lunch and buy a more powerful air pump so I can add another large airstone.

 

[Chad]

Surface agitation is one of the main tricks for gas exchange in a tank. Sometimes canisters don't do this very well. Airstones can and have been used for years but what I like to do is make sure the return on the tank is placed so that the water coming back in from the filter ripples the surface pretty well. 

 

[eduller]

Thanks for the input. I will try to adjust the water flow. The outflow tube comes in several sections, so I could try removing one so the spray is closer to the surface and will cause more agitation. Or I suppose I could lower the water level to be even with or lower than the spray if that doesn't work.

 

[Chad]

It's an experiment that's worth a try. Let us know if you notice a difference with greater surface agitation. 
Here's a video that shows what it should look like. 
 
http/youtu.be/rNlxXRnqp4Y

 

[eduller]

Ooh that's helpful. My surface is nothing like those. It's more of a gentle ripple. I think I'm so used to keeping just bettas that I underestimated how much rippling there needed to be!

 

[Chad]

And if it doesn't work then you simply put things back to how they were and we explore another possible solution. But right now the thing that pops into my head is oxygen. 

 

[Freedom]

I have a 54 gallon tank with the following stock:

• 10 harlequin rasboras
• 11 neon tetras
• 10 rummynose tetras
• 6 peppered cories
• 3 honey gourami

Every 2-3 days, the tetras and rasboras begin gulping rapidly with rapid gill movements. The gourami and cories seem unaffected.

The tetras and the rasboras are using their gills to collect oxygen, normally.  The gourami and cories are labyrinth fish, so they are getting the oxygen they need by going up to the surface -- much as your bettas do.  (You mentioned somewhere you are used to bettas).  This fits with it being an oxygen problem.
 
Interesting!  Let us know how it goes.

 

[eduller]

Okay I angled the outflow spout up as much as I can, and I also located the outflow in the back corner of the tank so the spray is spread across the entire surface of the water. See video link below. No one seems to be getting blown around too badly, although I can see how in some places the fish are feeling the current. I know the gouramis like stiller water, but they seem to all be going up to the surface for air without too much trouble. The cories however are having a lot of trouble getting up. I feel bad for the little guys. Should I create a more still area by angling the flow to one side or another, or do you think they will just get used to it or find a place where they can get up? Did I hallucinate that cories don't absolutely need to breathe air like bettas do, but they have the option if they need to?
 
 
http/s977.photobucket.com/user/eduller/media/20140421_200652_zpsf7d00e10.mp4.html

Also please ignore the extreme forest. I need to trim the plants a little, but I'm waiting to get my new 20g tank set up to have someplace to put all the trimmings.

 

[Chad]

Yes, you will have to play around to get it just right for the fish you are stocking. And it will take a couple of days like this in order to show if it's working or not working. 

 

[eduller]

All looked well this morning, but I didn't expect any problems. I did a water test (paranoia!) 0 amm, 0 'trite, 5ish 'trate. No heavy breathing, but I see the cories still having a hard time getting to the surface. The neons are also kind of freaking out I think. They are kind of lamely following around the rummynoses (who are much bigger). I think there is too much current for them.
 
Question - would a spray bar create less current while still allowing for surface agitation? I was thinking about kludging my own spray bar out of a section of aquarium tubing with the end plugged and holes drilled in it. That way I could have some holes drilled so that the water sprays up and along the surface and some that would spray out into the tank to maximize surface agitation while minimizing currents in the tank. I'd obviously have to put a couple of suction cups holding the tubing horizontal, but it seems like it would work as long as I make the holes smaller to larger so that all the water just doesn't flow out of the first couple holes.

 

[Chad]

The current should be the same. You didn't increase the gallons per hour just the location so in terms of actual force it's the same it's just circulating differently. Investigate the natural habitat of the fish and you will see many are used to fast flowing streams and rivers. 
 
A spray bar would also work. Before I did that though I would try lowering the return nozzle just a little or moving it to a different location like to the right or left corner. This will create a different flow pattern than having it in the middle. More of a steady rotation rather than a a random blow which is generally what's created by a center return. It comes from the center and hits the wall in front of it breaking it up. If the return is moved over to the far right or left (with the intake on the opposite side) it tends to create a flow the fish are more used to, flowing in one steady direction. 

 

[eduller]

Well, so far so good. Nobody's gasping. I moved the return nozzle off to one side which did help with the current. I couldn't quite get it into the right corner because of the versa-top, but I'm going to try it in the corner tonight without the top because the rasboras seem to be still having trouble with the current. All the tetras just swim below it, but the rasboras stay in the upper third of the tank mostly and instead of going to the other end of the tank where there's less current, they all just constantly swim into the current and look like they're just suspended in midair because they aren't making any progress swimming forward. Although maybe they like it because why would they keep doing it?
 
Thank you again for all the advice. I think if everything is still fine tonight, then oxygenation was definitely the issue and I'll call it problem solved. Last time, I did a large water change on Saturday afternoon and by Monday morning, the gasping had begun. That was only about a day and a half later.
 
Now to focus on healing my poor betta with dropsy This has been a stressful week fish-wise. Gasping fish tank, betta with dropsy, dwarf puffer has been refusing to eat and is now skin and bones. This is the most stressful hobby I've ever gotten myself into!

 

[Chad]

I've not had a betta with dropsy so someone else will probably be better able to help with that one.
 
I have had numerous dwarf puffers. They are not very competitive eaters against faster fish. The best hope for its health is to put it in a tank by itself, if it's not. Using a blood worm feeder is also a good idea for them, like the photo below, it's a little cone that you put the blood worms in. They come in different sizes and work best with live blood worms.
 
If you cannot put the puffer in a tank by itself or divide up the tank it is in then I suggest redoing the aquascape of one corner and put lots of tall plants (real or fake) in that corner so the puffer can use that to hide in and create a territory for itself. This is where you would put its food. The puffer is going to be weak and even less able to out compete other fish for resources so you have to do everything you can to make sure food gets by it. If you can get a hold of 20 or so pond snails that would be an excellent change for it to survive as it will eat them and the other fish won't.