ZooMed 501 vs Finnex PX-360 for under the tank's

[bastage]

So I have a 55g stand that has a Flora, a standard 10g & a Ebi all on it in a row. Currently I have an internal filter on the flora, a hob on the 10g & a ZooMed 501 on the ebi. Well this is in my bedroom & my wife wants it quiet so the HOB has to go. Well I want them pretty so the ugly arse internal filter in the flora also needs to go.

Currently the zoomed is behind the 10g with the pipes ran back behind the ebi. Well this wont work if I add another 2 canisters as there will just flat out not be enough room so the canisters are going to have to go under in the stand. Plus this just looks better to not have to see them.

So I have read that both of these filters wont work under the tank because they use gravity, well as someone who understands basic physics that's BS since the water pressure will always try to equalize & I know that the only real difference is in the resistance of the water flowing through the pipes. which should be limited.

So that said what is everyone's opinion of these 2 filters keeping in mind there will be several feet of tubing on each.

Also of note. I already have an aquatop and have nothing against aquatop/sunsun, but they don't make one small enough for me to get 3 of them in the stand easily since it only opens up in the middle. So please don't say I should get a sunsun as its not going to happen.

[OVT]

I have no experience with ZooMed 501 but I do have 3 Finnex PX-360 in operation. There are a number of posts, including mine, on this forum on the subject.

The short story, Finnex's claims aside, PX-360 has a practical head of about 6". I could not get any reliable flow with anything higher then that.

As far as the physics goes, if the flow was one-directional (down) all filters would have infinite head. The problem is that gravity is a vector. Therefore, something, i.e. motor, has to push water up against the gravity, tube resistance, water and atmospheric pressure.

[bastage]

Originally Posted by OVT

I have no experience with ZooMed 501 but I do have 3 Finnex PX-360 in operation. There are a number of posts, including mine, on this forum on the subject.

The short story, Finnex's claims aside, PX-360 has a practical head of about 6". I could not get any reliable flow with anything higher then that.

As far as the physics goes, if the flow was one-directional (down) all filters would have infinite head. The problem is that gravity is a vector. Therefore, something, i.e. motor, has to push water up against the gravity, tube resistance, water and atmospheric pressure.

The filter does not push against gravity. If the intake was low & just the output high then yes, but with both being sealed until it hits the aquarium which gives both sides the same water level. Your Atmospheric pressure also makes me lol since the only exposed atmosphere is the tank surface which its not pushing against since you are not raising the tank water level. The resistance of the tube is the only effect. Of which a change in materials from the standard rubber/nylon tubing can reduce.

[samamorgan]

Originally Posted by bastage

The filter does not push against gravity. If the intake was low & just the output high then yes, but with both being sealed until it hits the aquarium which gives both sides the same water level. Your Atmospheric pressure also makes me lol since the only exposed atmosphere is the tank surface which its not pushing against since you are not raising the tank water level. The resistance of the tube is the only effect. Of which a change in materials from the standard rubber/nylon tubing can reduce.

Everything you just said is completely wrong. That is all.

[bastage]

Originally Posted by samamorgan

Everything you just said is completely wrong. That is all.

[samamorgan]

According to your *flawless* logic you could put a filter 100 feet below the top of the aquarium and it would still pump just fine, because its just one big pool of water in a closed system! I'm so glad you enlightened me, I always thought the manufacturers were wrong when they talked about that head height thing.

http://www.aquarium-pond-answers.com...-and-pond.html

[bastage]

Originally Posted by samamorgan

According to your *flawless* logic you could put a filter 100 feet below the top of the aquarium and it would still pump just fine, because its just one big pool of water in a closed system! I'm so glad you enlightened me, I always thought the manufacturers were wrong when they talked about that head height thing.

http://www.aquarium-pond-answers.com...-and-pond.html

Great lets talk about head pressure..

Head pressure is the difference between the water level you are pumping from and the water level you are pumping to. If you are pumping out of your tank and back into it, the head pressure is 0.

(that was stolen from another thread here)

Another user in the same thread also worded it well..

There is exactly as much water weight pushing down the back side as the motor has to push up. The only difference would be the additional friction caused by the extra length. Some of this could be offset by moving up to the next size hoses.

[OVT]

At least the OP got my personal experience with Finnex PX-360. And you are welcome.
How that will be used is none of my business.

I will be swapping all of my Eheim 2075s for Finnex 360s with 3/4" tubes. Won't even have to plug the filters in - the pumps are useless anyways.

The last "scientist" that tried to defy the law of gravity left a nice wet spot on the ground. The supporting quotes give me hope for more wet spots in the near future.

We can LOL together once we are at the same level:

http://en.wikipedia.org/wiki/Hydraulic_head
http://www.engineeringtoolbox.com/pu...ure-d_663.html

[astrosag]

No head pressure, just friction. Sorry guys. Helping balance gravity is the pressure of the water column from the intake. Nice try though

[OVT]

Originally Posted by astrosag

No head pressure, just friction. Sorry guys. Helping balance gravity is the pressure of the water column from the intake. Nice try though

Indeed, with 0 flow, which is very useful.
If you can generate 1 gph flow at 1" head without external energy you would have the first ever working Perpetuum mobile. Nobel Prize is on it's way.

[Craigthor]

Eheim 2211's would be perfect for smaller tanks and placing the filters under the tanks.

[astrosag]

Originally Posted by OVT

Indeed, with 0 flow, which is very useful.
If you can generate 1 gph flow at 1" head without external energy you would have the first ever working Perpetuum mobile. Nobel Prize is on it's way.

Your sarcasm is cute. No, sorry not a girl - I know people don't say that to you often...but

In a closed system with 0 flow, you'll have 0 pressure at the top and the water column's weight (hydrostatic pressure) at the bottom - for incompressible fluid. Sure, one side is fighting gravity, but again, the other side is assisted by gravity. The primary thing a pump is fighting is friction which varies on pipe length.

You must be a political science major

P.S. To be a bit more clear, what I'm saying is head loss due to friction. I should have been clear but someone versed in physics would have understood when I said no head pressure in a closed system - just friction.

[astrosag]

Originally Posted by samamorgan

According to your *flawless* logic you could put a filter 100 feet below the top of the aquarium and it would still pump just fine, because its just one big pool of water in a closed system! I'm so glad you enlightened me, I always thought the manufacturers were wrong when they talked about that head height thing.

http://www.aquarium-pond-answers.com...-and-pond.html

Actually your example is a fallacy.

You're not accounting for the incredible friction loss from 100 feet of tubing. Now your logic is a bit less flawed!

[DerekFF]

Now that im thinking about it (no physics degree but i am Japanese so that gives me +10 math and science points yeah!??) :p
The physics behind a CLOSED system like a canister filter should only be effected by friction loss through the tubing and a super minimal head pressure loss where the water needs to be pumped over the lip of the tank and therefore above the water line. Sorry peeps but the laws of physics dont lie, and the key word or point here is that it is a CLOSED system aka canister filter

Sent from my DROIDX using Tapatalk

[astrosag]

^
Yes.