Tropical Fish Forum

Tropical Fish Keeping Help and Advice => Fishtank Filtration and Cycling => Topic started by: Cheryl on October 17, 2014, 02:51:32 PM

Title: Fluval U2 which setting?
Post by: Cheryl on October 17, 2014, 02:51:32 PM
Hi all, sorry if this is in the wrong place, admin feel free to move it.  ;)

My question is about oxygenating the tank, I have a Fluval U2 which is all foam media. But what baffles me is should I have it on the one that aerates the water or the on the gentle mid flow or should I have it on gentle flow and aerate at regular intervals?

I have micro devario and celestial pearl danios, some plants and hope to get some shrimp soon.
Title: Re: Fluval U2 which setting?
Post by: Sue on October 17, 2014, 07:00:30 PM
I have just downloaded the manual to see what the filter looks like.

It looks like there is an optional venturi attachment, then a knob that selects between top output, middle output or bottom output.
If I had a U2, I would opt for not attaching the venturi (always found them a nuisance on filters I've had) then setting the knob for top water flow. It implies you can also adjust the flow rate - if you can, I'd adjust it to the strength that stops short of turning the tank into a whirlpool.
Title: Re: Fluval U2 which setting?
Post by: dbaggie on October 17, 2014, 07:19:14 PM
I'd adjust it to the strength that stops short of turning the tank into a whirlpool.

Yes, if it pins your fish to the side of the tank then you've gone too far!  ;D
Title: Re: Fluval U2 which setting?
Post by: Gav on October 17, 2014, 07:39:36 PM
I have this filter and use the top output about 25mm below the surface so it just ripples it.
Title: Re: Fluval U2 which setting?
Post by: Cheryl on October 17, 2014, 08:00:42 PM
So just shut the venturi off then, excuse my ignorance here but why do people put air stones/lines in their tanks. I thought that I had been doing something wrong by not oxygenating my water.
Title: Re: Fluval U2 which setting?
Post by: Sue on October 17, 2014, 08:50:58 PM
People think they put oxygen in the water but they don't. Their only function is to look pretty, if you like that sort of thing. Well, I suppose if the filter was inadequate it would help with oxygenation but only because the bubbles churn the water up so more gets exposed at the surface. If the filter is creating enough water circulation, that is plenty for oxygenation.
Title: Re: Fluval U2 which setting?
Post by: Fiona on October 18, 2014, 12:45:43 AM
I've got this filter and because I have a heavily planted tank I use setting B with the venturi valve set somewhere in the middle range, otherwise all my plants would end up leaning at a 45 degree angle, I have an airstone set up opposite to ripple the surface of the water.

If you dont have that many plants or they're low growing setting A is great for aeration and circulation but like dbaggie said you may need to adjust the output or you'll have fish wall paper in your tank  ;)
Title: Re: Fluval U2 which setting?
Post by: Cheryl on October 18, 2014, 04:57:28 PM
thanks for that, so far I am avoiding the fish wallpaper  ;D