Current

[gems]

The filter that came with our tank (a Rena Filstar I1) has a function on it which adjusts the speed at which the water is passed through it. The current it creates is quite strong when turned to the maximum setting. We were wondering if we turn this down, will it affect the filtration power? Our Panda Corys don't go over to that side of the tank much, and when they do it seems they get quite tired trying to swim there. We have read that they don't like strong currents (although our Danios love it!), so we wanted to turn it down but are worried it might have an adverse effect on the water quality.

Thanks

 

[mark.w.jones]

The filter that came with our tank (a Rena Filstar I1) has a function on it which adjusts the speed at which the water is passed through it. The current it creates is quite strong when turned to the maximum setting. We were wondering if we turn this down, will it affect the filtration power? Our Panda Corys don't go over to that side of the tank much, and when they do it seems they get quite tired trying to swim there. We have read that they don't like strong currents (although our Danios love it!), so we wanted to turn it down but are worried it might have an adverse effect on the water quality.

Thanks

The optimal rate for tank filtration is 5x your tank volume per hour. So your filter needs to run at about 290l per hour for your tank size.

Presume yours is something like this:

http/www.aquatics-online.co.uk/bigpics/filstarinfo.htm

If you have the iV1 this only runs at 220l per hour so to be honest you are a little under filtered. The iV2 would have been a better option but then that's obviously not your fault

Therefore, in a roundabout way I would suggest you dont reduce the flow rate at all. Maybe rena do some sort of spray bar attachment to spread the outflow from your pump.

 

[andywg]

Both danios, and corries, come from fast flowing streams so will appreciate the extra current.

 

[gems]

Checked our filter, it isn't an IV1, just an I1, although I check the I1 profile online and it's a totally diferent thing! I can't find our filter anywhere on the net. The I1 specs I could find are below

Flow Rate : up to 300 lph (60 gph)
- An extremely compact and powerful filter, with maximum performance and ease of use.
- Complete with mounting suckers and sponge media
- Dimensions : 11.7cms x 4.7cms x 4.3cms : 4.5watt motor
- No facility for air diffusion, nor flow adjustment.

That says there's no facility for flow adjustment, but ours definitley does have that facility. I'm pretty sure it's not an IV1 because it doesn't need an air pump. How confusing.

 

[mark.w.jones]

Checked our filter, it isn't an IV1, just an I1, although I check the I1 profile online and it's a totally diferent thing! I can't find our filter anywhere on the net. The I1 specs I could find are below

Flow Rate : up to 300 lph (60 gph)
- An extremely compact and powerful filter, with maximum performance and ease of use.
- Complete with mounting suckers and sponge media
- Dimensions : 11.7cms x 4.7cms x 4.3cms : 4.5watt motor
- No facility for air diffusion, nor flow adjustment.

That says there's no facility for flow adjustment, but ours definitley does have that facility. I'm pretty sure it's not an IV1 because it doesn't need an air pump. How confusing.

Well that sounds fine. Is there no way to attack some tubing and a spray bar then to diffuse the flow. Or is the outflow not from a nozzle.

 

[TwoTankAmin]

A common misconception is that higher flow rate = greater filtration. In fact the most important issue is the volume of media. At a slower rate the water passes through the media slower and is in contact with it longer. A great eaxample of this is the Eheim canister line- their Pro II flows at a rate of 250gph and is suffiecient for a tank up to about 90 US gals.

I run a lot of AquaClear power filters on my tanks and I have most of them set to the lowest flow rate. If you are worried about current, one solution is to use a pair of smaller filters, one at each end of the tank, rather than a single larger one.