water aeration/turbulence for oxygention for plecs

[guppylover2]

hi there,

have recently set up new 40g tank with water from established tank (and media) and have one gold nugget and 2 gibbies (will get 6 foot tank later to accomodate size). have a fluval 204, put output nozzle halfway down tank to better simulate river current. this is my first mainly pl*co tank, have driftwood and rocks etc. just wondering if i need to add airstone or other method of increasing turbulence at water surface/oxygenation. i know these catfish are used to fast flowing rivers with lots of oxygen. catfish seem ok, have only been in new tank for 5 days (prev small quarantine tank) in fact the gold nugget is way more sociable and is quite active even during the day. however my 2 guppies whom i just moved out of the tank were hanging out at the water surface sucking air, and very occasionally (have seen this only 2 times each with all the plecs) the plecs go up to the surface for air. maybe not enough oxygen? need an airflow unit? my ph, nitrates etc are all excellent.

what do you guys reckon? i really want the best for these fishes, i'm obsessed with them at the moment.

[Ira]

Since you only have one outlet you're better off putting it at the surface. It's normal for the plecos to occasionally swim up to the surface and grab a gulp of air and not particularly unusual for the guppies to hang around at the surface. But, anyway, move the outlet to the top so it's airating better and see what happens.

[HummingBird]

If you have your output agitating the surface you should be fine without an air stone.

[guppylover2]

thanks guys. will put output at surface. thinking of buying another air pump anyway, and will use a sponge over the air stone - will double as a sponge filter, plus will agitate the surface.