My fish aren't at the surface gulping for air, but is it just good practice to increase the amount of oxygen in the water? If so, how do you know if you need a power head or just a bubbler? And how do you know what size to get? My filter stirs up the water quite noticeably and I'm thinking of getting a second filter, so maybe this adds enough oxygen? This seems like shooting in the dark!
Adding more aeration will raise your ph slightly.
Adding a powerhead will increase current as well as aerate (if you have a venturi feature on it). Bubbler just adds air, but not as much as a powerhead will (since a powerhead pointed towards the surface will move more surface area and allow oxygen exchange than a bubbler)
Powerhead is usually quiter.
If your fish dont gasp for air ever, i dont see the need, especially since you already are battling high ph. However, since putting in two powerheads instead of my bubblers, my fish have very different personalities... they enjoy the current and are much more lively, they seem energized.
Does your filter output sit level with the water or does the water cascade in? Two filters will create twice the stir obviously, so that would be good. Depends on what you want to achieve.
How does the pH rise with more aeration? I know if you have co2 added to your system it partly converts to carbonic acid and as you agitate the surface you remove excess co2 thus reducing carbonic acid, but other than this how does agitation raise pH?
If you have fish with very large fins compared to their body size you probably don't want too much current in your tank.
Zambize. Do you have an undergravel filter on your tank?
heavy aeration, from what i've read, releases the co2 in your tap water, thereby raising your ph. Likewise, if you inject co2 into your water, you will lower your ph.
I wouldn't worry about extra aeration influencing pH. The benefits far outweigh any if any pH change without the use of added co2. Circulation is good for the fish as it gives them some exercise as long as it's not excessive. It also keeps junk from settling as much and allows the filter to take it in better.
I've got one Penguin 150 that agitates the water quite noticably and I'm about to add a second Penguin 150 to the tank. I'm thinking that these two filters, turned up high-ish, will agitate the water enough for my 28 gallon tank to aerate? My tank is also flatter and more squat than some at 24" wide, 19" tall, and 12" deep. It's a bow-front, which provides even a little more surface area. Can you have too much oxygen in your water?
I dont believe you can have too much oxygen in your water unless you are growing live plants. Other than that, your fish will love the aeration. I think the added filteration will be more than enough agitation.... just let the water cascade atleast a half inch from the output to the surface of the water.
The short answer is no, you cannot over oxygenate your tank. Just by aggitating the surface, there is no way you are going to be in trouble of super saturating the water - it just won't happen so don't worry about it.
Now, just for your knowledge, it is possible to oversaturate your tank if it is heavily planted, you use very intense lighting, little surface aggitation, CO2 injections, ect. I don't believe this applies to you though.
