Question About Water Levels

[CBTF]

I just did a water change, this time I filled my tank literally to the top of the black rim. It is now very leveled with my hood. The filter is actually below the water now (where the water is supposed to stream out). I have noticed that because of this there is very little water action, but im sure it's still being oxygenated well enough.

So basically are there any harms of filling RIGHT to the top? I can't imagine any, the only thing I could think of was my betta jumping out easier but when push comes to shove 1 cm does nothing iin that case anyhow (yes, hood is on the tank- just a small space where the filter goes.)

Just making sure. It looks nice and the fish really seem to dig that extra little space.

 

[Tolak]

The only problem with filling it to the very top is if you have to stick your arm into do some sort of maintenance. Smaller tanks overflow, I learned the hard way.

 

[CBTF]

Ah. Well I had my hand in just now and it's good. 10G.

Find a cure for the many cathairs in there and win a prize

 

[SamUK]

if your filters too far under water then it wont create any surface movement which will mean theres no oxygen getting to the water.

you need a bit of surface movement/ripples for that reason.