how to make AC powerhead 70 aerate more?

[.:brianlovesfish:.]

i have an aquaclear powerhead 70 with quick filter attachment and it seems to have trouble aerating...the spout/outlet is roughly 5-6" below the surface and is having trouble...it aerates fine when near the surface (hang on back bracket)...

so, ive experimented and started to cut roughly 1/2" of tubing at a time to see if it would promote the "venturi effect." am i wrong to assume that the less amount tubing, the easier it is to suck air? also, i am aware that i can modify my powerhead, but i expected a powerhead rated for 70+ gallons would be able to handle aeration on bottom of a regular sized tank...any tips? is there something im missing?

[toddnbecka]

The deeper you place the powerhead, the harder it is for it to pull air against the water pressure. Attach a small air pump to the venturi line. You don't need a deep-water air pump, just something to push the air a little more to reach the powerhead.

[.:brianlovesfish:.]

oh yeah, i realize the concepts and mechanics behind it, but i expected more from a powerhead that was powerful enough to be rated for aquariums up to 70 gallons...mine stops aerating a few inches from the surface! i noticed in my friend's parents' aquarium, they have the same AC powerheads and they aerate more than mine under water...maybe mine is defective =\

[Lady Hobbs]

Aquarium filters are generally rated for just about half of what they can really handle for filtering purposes.

[Cristoff]

Try popping off the quick filter and see if that helps. I use those filters on my AC 50 powerheads and have noticed that they slow the water flow enough to stop the aeration.

At least then you can rule that out if it still doesn't help.