How can I hook up one Fluval 304 to two 20 gallon tanks?

[Prince]

what pvc pipe configuration should i use to filter two 20 gallon tanks with one Fluval 304. I am concerned that one tank with receive better filtration than the other. Would the best tank set up be side by side or stacked. I don't want to drill the tanks so these will be over the rim PVC hook ups.

 

[AndyNarwhal]

You can't do it. Without an overflow system there is no way you can regulate that the water going into each tank will be the same as the water going out. It is just an overflow waiting to happen.
Andy

 

[Tony]

Like Andy said, without bulkheads, you do risk overflowing the tanks.

You could try an inverted U-pipe to keep a siphon in between the two tanks (on the same level). The inlet would be on one tank and the return on the other.

Alternatively, you could drill one tank, install a standpipe through the bottom or side and stack the two tanks on a stand. The filter return would be in the top tank, with the filter inlet at the bottom tank.

Or you could just use sponge and box filters.

EDIT: If you do decide to go with the siphon, drill a small hole in the PVC and install a device called an Aqualifter pump. This will ensure that the siphon tube does not fill with air and you lose your siphon. These things are a necessity for undrilled saltwater setups with over-the-side weirs.

 

[UNCLERUCKUS]

Like Andy said, without bulkheads, you do risk overflowing the tanks.

You could try an inverted U-pipe to keep a siphon in between the two tanks (on the same level). The inlet would be on one tank and the return on the other.

Alternatively, you could drill one tank, install a standpipe through the bottom or side and stack the two tanks on a stand. The filter return would be in the top tank, with the filter inlet at the bottom tank.

Or you could just use sponge and box filters.

EDIT: If you do decide to go with the siphon, drill a small hole in the PVC and install a device called an Aqualifter pump. This will ensure that the siphon tube does not fill with air and you lose your siphon. These things are a necessity for undrilled saltwater setups with over-the-side weirs.

GREAT POINT TONY. THE EDIT IS THE MOST VALUABLE. THAT AQUALIFTER IS SO LIFESAVING.

 

[danger_chicken]

EDIT: If you do decide to go with the siphon, drill a small hole in the PVC and install a device called an Aqualifter pump. This will ensure that the siphon tube does not fill with air and you lose your siphon. These things are a necessity for undrilled saltwater setups with over-the-side weirs.

These are great unless you do what I did last weekend and knock the aqualifter return tube out of the tank without noticing and drain 60% of the tank on the floor. Luckily it was only a 5g tank.

In theroy something like this could work: build two T's off the 304 with one side going to each tank, the plumbing should be exactly the same lengh going to both tanks, add a gate values near the tank. Adjust the values to equalize input an out to each tank. Only attempt if you like adventure. I do. Drawling is not to scale.

 

[lonlangione]

If you sit the tanks next to each other and use a "U" tube with stainers on both sides it will work. Just be sure that the stainer on the tank with the inflow doesn't get clogged up. Also if the "U" tube loses it siphon the tank with the inflow will overflow.

 

[Tony]

DC- You have to have bigger ones than I do to try something like that.

 

[Jumbie]

Danger knows his stuff doesnt he Tony lol.

 

[Tony]

Danger knows his stuff doesnt he Tony lol.

It is a very nice picture, yes, but sort of a nutty idea.

Sort of like if While-E-Coyote decided to keep fish..... ACME FISH FILTER. lol.

(No offense, Mike )

 

[danger_chicken]

lol the Coyote is my childhood inspiration, he never gives up!

 

[Tony]

lol the Coyote is my childhood inspiration, he never gives up!

Ahhh.. now things make a lot more sense. :happy0007:

 

[Reel Addiction]

Funny thing is, while reading I was thinking the same thing as Mike??? Let er rip!

 

[jonclark96]

I think sponge and/or box filters is much more fail safe. I would think that balancing the valves to have even intake and return to the tanks would make you want to pull your hair out.

 

[lonlangione]

When I was 14 I hooked up 10 - 10 gallon tanks with u tubes in each tank and a diatom filter intake in one end and a return in the other end. I ran these tanks for many years this way with no problem at all. The only thing that will naturally happen is the levels in the tanks will drop slightly from the return tank to the intake tank. I was ahead of my time, that was 40 years ago.

Lonny

 

[danger_chicken]

I think sponge and/or box filters is much more fail safe. I would think that balancing the valves to have even intake and return to the tanks would make you want to pull your hair out.

I think it would be easier then balancing a w/d, once it's set it shouldn't need much adjusting. That's also why I say use gate valves instead of ball valves. You can make much smaller controlled adjustments. I may have an fx5 freeing up in a few weeks, maybe I'll try and hook up all of the small tanks in my back room to that one filter I like where this idea is going Prince. This deserves a :jumpy:

 

[AndyNarwhal]

It's not going to work danger. All it takes is a small piece of debris to cover over the inlet strainer, a change in water level to one of the tanks, a buildup of gunk inside the lines, etc... to change the flow rate and if you are not there to adjust the valve one of the tanks is going to overflow.
Linking the two tanks together with a siphon between the two works because gravity causes a fluid to be self leveling. As you take water from the downstream tank, water flows from the upstream tank through the siphon in order to equalize the water level. This would happen whether water was being pumped into the upstream tank from the Fluval return or not. This also only works if the siphon is maintained (hence the need for the aqualifter) and if the maximum water flow capacity through the siphon is greater than the actual flow rate of the water entering the upstream tank. If too small of a siphon is used the water level in the upstream tank needs to raise in order to build up greater pressure to equalize the flow. If there isn't enough vertical clearance the result is an overflow. but I suspect a typical 1"-1.5" u tube is sufficient for the flow from a Fluval 304.
Still this leads to water quality issues as the downstream tank will not be receiving clean, filtered water. Instead it will be receiving the dirty water from the upstream tank. How much of a difference this makes is hard to quantify. It might be a problem or it might not.
Andy

 

[minifoot77]

I think it would be easier then balancing a w/d, once it's set it shouldn't need much adjusting. That's also why I say use gate valves instead of ball valves. You can make much smaller controlled adjustments. I may have an fx5 freeing up in a few weeks, maybe I'll try and hook up all of the small tanks in my back room to that one filter I like where this idea is going Prince. This deserves a :jumpy:

you can do it mike

 

[danger_chicken]

Still this leads to water quality issues as the downstream tank will not be receiving clean, filtered water. Instead it will be receiving the dirty water from the upstream tank.
Andy

This is what I didn't like about linking them daisy-chain style. I think all of the things you mention pose the same risks when connecting mutiple tanks to one filter, no matter what type of filter. Even on a drilled tank if the overflow gets clogged you're wet. That's where the adventure part comes in.

 

[AndyNarwhal]

Not really danger. If the teeth/strainer in an overflow gets clogged the water can always spill over the top of the overflow and into the drain preventing the tank from overflowing. That is why the tops of overflow boxes are below the lip of the frame. There is no backup mechanism in a siphon. Also keep in mind that should for some strange reason, an overflow become completely clogged only the few gallons of water in the sump of the filter is going to overflow the tank. But since the intake strainers of a canister are most likely located near the bottom of the aquarium the result is that one tank will overflow and the other tank will drain itself down until the siphon sucks air. Consequently draining one tank and greatly increasing the volume of water spilled onto the floor.
Trust me. Filter design is part of what I do for a living. I know what I am talking about. But if you still don't believe me go ahead and try it. After all it's not my floor you will be soaking.
Andy

 

[lonlangione]

You will never know unless you try it.