If u don’t want an air stone then just lower ur water level so if u have a hob filter it makes more surface agitation but the sound can annoy u. A mini waterfall sound
Having a current from your canister doesnt count as “surface agitation”. The top of the water needs to agitate and bubble and touch the air so there is gas exchange.
Having a slight current underwater is not that lol
It sounds like my last resort before I return my fish is to get an air stone. Does anyone have any brand recommendations? My local petco has top fin but I’ve learned long ago to not trust petco.
This is my first tank, and I have no idea why this is happening. I have good surface agitation (Lily pipe is above the surface and creates waves), and all of my water tests show no ammonia, nitrates, or nitrites. KH is 2 and GH is 5. Clearly this appears to be an issue with oxygen, but with surface agitation I have now, there should technically be no issues. Could someone help me understand why my fish gasp for air when the lights go off?
The tank, FYI, is a 20 gallon long. Heavily planted. It should be cycled now—I left it for 6 weeks before I finally added fish, and have been adding nitrifying bacteria since I started the tank.
Sometimes shrimps like to hang out by the heater where it’s warm.
I would also put your heater vertical.
Can’t go wrong with air stones like many others have said.
I’ve never heard of the plants taking up all the oxygen in the tank when the lights are off but I’m sure it’s a real thing..i would however turn them off as much as possible to reduce stress. A 12/12 timer would be good
Yep, this is no joke I lost a lot of fish to this one morning by overfilling after a water change the day before (and thus not getting surface agitation)
You just need good surface agitation. I have a diy co2 system that runs 24/7 on a 10 gallon which only has moss and hairgrass in it and never had an issue with low oxygen or stuff gasping etc by simply having a hang on back filter
You should also check your ammonia levels. They do the same thing when ammonia begins to rise.
Yes, aeration is important, but as someone who has never used an air stone but plant very heavily and use a simple HOB, I’ve never had this issue, except when I accidentally reset my cycle.
river4308 
Plants stop *producing* oxygen when the light is out. Increase surface agitation with bubbles or by directing the filter outflow at the surface.
If u don’t want an air stone then just lower ur water level so if u have a hob filter it makes more surface agitation but the sound can annoy u. A mini waterfall sound
Your water is like glass.
Having a current from your canister doesnt count as “surface agitation”. The top of the water needs to agitate and bubble and touch the air so there is gas exchange.
Having a slight current underwater is not that lol
If your fish and plants can handle it, lower temp! My fish completely stopped doing this just by me lower the temp to 72-73
Add an air stone
I feel like I’m missing some context on this tank.
Should I assume you are running CO2
If you have co2 running turn it off at night
It sounds like my last resort before I return my fish is to get an air stone. Does anyone have any brand recommendations? My local petco has top fin but I’ve learned long ago to not trust petco.
This is my first tank, and I have no idea why this is happening. I have good surface agitation (Lily pipe is above the surface and creates waves), and all of my water tests show no ammonia, nitrates, or nitrites. KH is 2 and GH is 5. Clearly this appears to be an issue with oxygen, but with surface agitation I have now, there should technically be no issues. Could someone help me understand why my fish gasp for air when the lights go off?
The tank, FYI, is a 20 gallon long. Heavily planted. It should be cycled now—I left it for 6 weeks before I finally added fish, and have been adding nitrifying bacteria since I started the tank.
Sometimes shrimps like to hang out by the heater where it’s warm.
I would also put your heater vertical.
Can’t go wrong with air stones like many others have said.
I’ve never heard of the plants taking up all the oxygen in the tank when the lights are off but I’m sure it’s a real thing..i would however turn them off as much as possible to reduce stress. A 12/12 timer would be good
Yep, this is no joke I lost a lot of fish to this one morning by overfilling after a water change the day before (and thus not getting surface agitation)
Get a very low wattage pump and place it on top of the water column, turn it on at night.
I had this problem despite a heavily planted tank. I added air stones and an air pump and it was instantly solved.
Assuming all your water parameters are good, adding an air stone + angling your lily pipe towards the surface should do the trick.
Run an air stone 24/7. Worst comes to worst your airstone bogs up with algae and you have to swap it out
There is barely any surface agitation you should add air stones to increase
You just need good surface agitation. I have a diy co2 system that runs 24/7 on a 10 gallon which only has moss and hairgrass in it and never had an issue with low oxygen or stuff gasping etc by simply having a hang on back filter
Get yourself an air pump and air stone and put it on a timer to run during the evening
How many fish and shrimp are in the tank?
Just buy a oxygen pump and run thru night time coz daytime plants gives 02 but nighttime it’s vice-versa.
Too much CO2
Definitely need more oxygen in that tank if everyone’s gathering up top. Air stones are great for surface agitation!
I use those too. They last for 9 mos to a year in ime
You can add a valve to dial down the intensity of you want. Aquarium coop sells those too
You should also check your ammonia levels. They do the same thing when ammonia begins to rise.
Yes, aeration is important, but as someone who has never used an air stone but plant very heavily and use a simple HOB, I’ve never had this issue, except when I accidentally reset my cycle.