I have just solved a problem and wanted to share with other newbies.

I had been relying on the spray bar for aeration in my 3' planted community tank I had though/been told that should be enough...WRONG!

I have lost a few of my inhabitants off and on in the last few weeks and I had noticed they were breathing very fast compared to my 2' tank fish.

Their gills were very pink and I had started to suspect I had some major issues. My water tested out fine, and I even check ammonia levels twice suspecting an ammonia spike from an un-found dead fish.

Last night I hooked up an airstone in the tank, within 10 mins the fish had stopped gasping and activity in the tank increased dramatically.

I suspect the pink gills are gill flukes taking advantage of my fish's weakened state.

I hope this helps someone in the same boat

I think you are right on the money - a lot of tanks have very poor gas exchange due to a lack of circulation within the tank and particularly poor water surface movement which causes poor aeration, a weak biofilter, and also allows algae to grow. I've managed to get enough from just a spraybar, but it has a big pump on it. Another thing people often overlook is floating plant leaves, like on Tiger Lotus etc - they do a pretty good job of halting gas exchange, so it is worth keeping them in check too.

did you have your spraybar angled so that the water was breaking the surface or at least creating a current you could see on the surface? if not it's likely that it wasn't doing much aeration...

How heavily stocked is your tank? if your stocking levels are high enough that you require additional aeration (either from an airstone or the spraybar) you might be overstocked....

Red and inflamed gills are an indication of an ammonia spike (and perhaps stress from lack of oxygen as well). Now that they have stopped gasping give them a few days and see if the redness/pinkness goes away - its much more likely to be related to the lack of oxygen in the water than flukes (unless you've already had an identified case of that?)

You don't need any aeration unless your tank is stocked heavier than the tank can support naturally. Aeration is a way of getting away with overstocking. Having said that when seriously breeding fish I used to overstock and overfeed to a mighty degree. It does make for a lot of work though. I have a 1200 tank with an electric sponge filter only and heavily planted which seems to keep the temperature pretty even and the fish and plant happy. Aeration will drive CO2 from the water and that is good for plant growth.

Remember too that the warmer the water the less oxygen so in summer you may have more trouble than other times.

& its not the air from the airstone that oxygenates the water is the water disturbance on the surface. i dont have an airstone in my 200L, just use the spraybar to agitate the surface.

you could also try a surface skimmer. i have one and it's brilliant at removing surface film so that there's maximum gas exchange. two good types are the eheim and then the hagen/aquaclear. as already stated, ripples and surface disturbance are good as they increase the surface area for oxygen exchange. you could also try and cultivate your plants so that they do produce oxygen and remove ammonium from the water (at a pH below 7).

Aeration will drive CO2 from the water and that is good for plant growth.

i'm sure it was just a typo, but a lack of CO2 is NOT good for plant growth.

It won't drive CO2 out, not exactly. It will just make sure it's closer to in balance with the atmosphere. So, if you have a lot of plants using up a lot of CO2 so the amount in the water is less than that, airation will increase the amount of CO2 in the water.

Sorry, I wasn't very clear. I meant aeration drives off CO2 and CO2 is good for plant growth so aeration is not always a good thing.

Some water supplies suffer from high iron which tastes terrible and stains. The way to get rid of it on the cheap is to aerate it. This drives CO2 off and that is what keeps the iron in the ferrous state. Ferric iron is almost insoluble and can be settled out. Water has a greater affinity for O2 than CO2.

Sorry, I wasn't very clear. I meant aeration drives off CO2 and CO2 is good for plant growth so aeration is not always a good thing.

in a planted tank with no fish

It has fish. That is where the fancy fertilizers and CO2 injection come from.