Just to be clear on the media for the aquaballs:
The 130 has 2 baskets and a small container under the pump and the 60 has one basket and a small container under the pump. The baskets all have slits in them so if you use filter wool in the bottom basket of the 130 the debris will still get into the sponge in the basket in the upper basket.
They are designed to have sponge in all the baskets and more sponge or filter wool in the space under the pump.
Oh yes, Essjay is right. I had forgotten about this part as I used this filter quite some time ago.
There are slits on every compartment. Sorry, for my misinformation.
So, my idea of putting filter wool at the bottom may not work.
I think the only way is to slice(or even peel it off with your fingers) a thin piece of filter wool and wrap around the sponges that come with the filter.
But if it's too troublesome for you, then just forget about it.
The sponge alone should be good enough.
I didn't use the venturi (bubbler). I had the 125 litre first and that was in the lounge. When I tried the venturi my husband complained the bubble noise interfered with his music. When I got the 50 litre in the kitchen it never occurred to me to use it, nor when I got the biopower in the 180 litre which is in the dining room.
I use the mini spray bar on my filter.
One thing I like about all Eheim products is that the suckers are widely available. I've had filters in the past where the suckers were not removable and suckers do not stick on the glass forever. They stop working when they get old and rigid, and with Eheim you just get replacement suckers. Just be careful how you remove the old ones.
I find that Eheim venturi isn't as quiet as some other brand like Aquael. But if I'm not wrong, if you reduce the flow rate, the noise will be lowered down.
Or if you don't want to use the venturi, you can use the spray bar which serve almost the same function.(as what Essjay did).
I agree that one of the disadvantage of Internal filter is the suction cup that will become harden and rigid after a while and it won't be able to stick to the glass any more.
For this point, I find that hang on filter or top/overhead filter has the advantage over internal filter.
Another disdvantage of internal filter as compare to hang on filter or top/overhead filter is the cleaning part.
They take slightly more time to clean than hang on filter as the filter are inside the tank rather than outside.
I think I should have pointed out this earlier.
But in term of noise level, internal filter is definitely better than the hang on filter.
I can hear my hang on filter water dripping down every night unless I fill up the water to the same level as the water outlet. But I want the water level to be slightly lower in order to create the water fall effect and to improve the water aeration.
In my conclusion, I find that all filters have their pros and cons.