Reducing Flow for an FX4

[Brogs]

So i attempted to use a Fluval FX4 on a 75 gallon discus grow out tank a while ago, only to find the current was to much for the fish to handle so took it down and have since been using sponge filters for all of my discus tanks.

Well recently i bought my wife a Fluval Spec evo 5 gallon tank for a baby betta(happy wife happy life). After setting the tank up the poor baby was being blown around the tank by the filter pump, thinking quickly i used a prefilter sponge and a cable tie to cover the output. It worked wonderfully and the betta couldn't be happier and left me thinking could this work on a larger scale?

Has anyone done this? Would it cause damage to the canister? I was thinking get some pvc pipe and drill a few holes, then put a pre filter sponge over them.

 

[deeda]

You are using a FX4 canister filter on a 5 gallon aquarium?

 

[Brogs]

No, the 5 gallon has the filter that was built into it, it was just an example. I currently have a FX4 on each of my 125, 90 and 75 gallons and a FX6 running my 110 gallon. The issue i ran into with the FX series is to much flow for my discus tanks.

 

[Backfromthedead]

You can adjust the output flow using the output valve right on the filter.

 

[duanes]

If you put a ball valve on the outflow line you can control flow, without harming a centrifugal pump (impeller driven).
If you throttle back the water coming in, there is a chance of burning up the pump.
You could also put a Tee or two on the line dividing flow.
Or make a long spray bar out of PVC, (as long as the length of the tank) with many holes that disperses flow over a large area, spreading out the flows force.

 

[Brogs]

I read online somewhere right after i bought the filter that you can cause damage to the seal on the valves doing that

 

[Brogs]

Installing a second ball valve could work, no risk of damage to the filter valve.

 

[deeda]

Sorry about that, I thought you were asking about using it on a 5G tank!

You can adjust the output valve slightly to reduce the flow without worrying about damaging the filter pump or the valve seals.

Duane's suggestion on making a DIY spray bar to replace the output nozzles would help to spread the flow more evenly compared to the nozzles.

 

[Brogs]

I moved some of my discus over to my stingray tank today to test using the filter valves, works well. Worst case scenario i order a new valve.

 

[Rob909]

+1 on adding a spray bar to the return. I think that’s going to be your best bet and you don’t have to worry about burning up your pump. You can even point the spray bar up at the waters surface so you get the surface agitation (better oxygen exchange). The longer your spray bar, the more the flow is dispersed, the less powerful the flow becomes.