Canister filter to powerful.

Hi all.
I just got a Fluval 307 canister filter as a gift for my 36g bowfront and it's way too powerful for the tank. My fish can't swim I tried multiple different placements in the tank to see if I could lessen the flow and nothing helped.

My questions are:
1. Is there a way to make it less powerful, so I could keep the canister filter?
2. Should I buy another one that might work better in the tank? I saw Fluval has a 207 canister meant for a 20-40 gallon with 206 gph.
or
3. Should I just purchase a different HOB filter? If so, which one?

I'm trying to get a new filter just to rule out what is leaking from my tank. I'm 90% positive that one of my HOB filters is slowly leaking but I can't prove it because I have a full cover lid that produces a lot of condensation that could potentially be the problem, in which case I'll replace the lid as well.
My current setup is 36g bowfront, Aqueon 10 quiet flow (100gph), and an Aquaclear either 20 or 30 (can't remember which one 100-150gph).

Current fish:
1- Endler guppy (that's most likely going to end up in my 10 gallon)
5- Dwarf clown barbs
1- Rubber lip pleco.

 

There are a few canister filters that have a variable speed pump. The SunSun HW3000 is one of them. It can get up over 700 gph, so I run it at half speed in my 40 gallon breeder tank.

One of the best ways to reduce flow is to get a prefilter sponge for the intake. Not only with that reduce flow through the filter, but it will also remove a lot of the debris from the water so you won't have to clean the canister as often. If is a lot easier rinsing out the sponge when you do a water change than it is dismantling the canister.

The more filter media you pack into the filter, the greater the pressure drop and the lower the flow will be through the filter. Cram as much into the filter as will reasonably fit.

The other thing you can do is diffuse the outflow from the filter. You can use sponges or water bottles with holes or slits to do this. You can also connect pieces of PVC pipe together with elbows and tees to divide the flow into several outlet streams. The volume of water flowing is not the problem. The fish have an issue due to the velocity of the water. By splitting the flow, you reduce the velocity without reducing the flow.

 

There are a few canister filters that have a variable speed pump. The SunSun HW3000 is one of them. It can get up over 700 gph, so I run it at half speed in my 40 gallon breeder tank.

One of the best ways to reduce flow is to get a prefilter sponge for the intake. Not only with that reduce flow through the filter, but it will also remove a lot of the debris from the water so you won't have to clean the canister as often. If is a lot easier rinsing out the sponge when you do a water change than it is dismantling the canister.

The more filter media you pack into the filter, the greater the pressure drop and the lower the flow will be through the filter. Cram as much into the filter as will reasonably fit.

The other thing you can do is diffuse the outflow from the filter. You can use sponges or water bottles with holes or slits to do this. You can also connect pieces of PVC pipe together with elbows and tees to divide the flow into several outlet streams. The volume of water flowing is not the problem. The fish have an issue due to the velocity of the water. By splitting the flow, you reduce the velocity without reducing the flow.

Thank you. I'll look into the suggestions you gave me and see if I can get any of them to work for me.

 

Something I've done is to make my own spray bar of sorts. I took a piece of PVC pipe and drilled a lot of holes in it, and attached that to the outflow of my filter. If you do it right, you can disperse the flow evenly across the whole surface area of the pipe. And, this, in turn, makes for much gentler flow.

 

Fluval now sells spraybars for their canisters. After a self made rainbar I purchased the Fluval bar and it works great. I direct the water at a 45° angle up and against the back glas wall and it works perfect.
Having the superior filtration, I think the 307 is perfect for your tank size.

 

I was just looking at the spray bars. I'll probably pick one up along with a pre-filter sponge to see how much I can slow things down. I'm so thankful for the ideas and suggestions.

 

Just a word of caution with the pre-filter.
I made the mistake to replace the little plastic cage and ball valve with a sponge, and the suction seems to be too powerful for the sponge to keep its shape, it slowly blocked the flow.
If you can find or make a sponge that fits over the cage, that should work.

 

Just a word of caution with the pre-filter.
I made the mistake to replace the little plastic cage and ball valve with a sponge, and the suction seems to be too powerful for the sponge to keep its shape, it slowly blocked the flow.
If you can find or make a sponge that fits over the cage, that should work.

I watched a video on how to make one for Fluval using one of their filter sponges. It fits over the basket. I was going to try that first to see how well it does.

 

Just drilling the holes in the spray bar larger will help some. the larger you drill them, the less current in the tank.

 

You can reduce flow of the x07 Fluval's by lifting the valve handle just slightly that's mounted to the main valve body on top of the canister.

Also, fldspringer made a very good suggestion. Ive used that trick before on a Hydor canister and it worked well