Connecting To Seperate Tanks?

[Toby_H]

I used this concept in this Rack I built:

That pic was taken before the system was actually functioning, but here is a conceptual drawing:

Water was pumped from the main tank (75 gal) to the end tanks (10 gal) then siphons drew water from the end tanks back into the main tank.

I built it so the top lip of the end tanks sat about 2" higher than the lip of the main tank. When I did water changes I turned the pumps off and refilled the tank to a level that did not allow either tank to overflow.

lol a 1inch tube could handle 250gph. I would go larger for insurance... dont want it getting clogged!

Not so fast there...

In the DIY there is a thread that usggests the "maximum" flow rate of different diameter pipes/hoses. But we should not foolishly assume that every pipe or hose will flow at the maximum flow rate. That chart/thread clearly explains that there is a minimum drop required to acheive the maximum flow rate.

We all know when siphoning water out of a tank, if we want to slow the flow of the hose we raise it up. This is because the flow rate of the siphon pipe/hose is directly dependant on the distance below the main tank's surface the pipe/hose releases.

Well in the case where we are siphoning water from one body to another, such as one tank to another, the flow rate is directly dependant on the elevational different between the water surface of the two tanks.

Since in my case (pictured above), and in the case the Original Poster is asking about, the water surface of both tanks connected by a siphon are at almost the same elevation, the siphon will function very slow.


In my situation photo'ed above, the functioning difference in water surfaces between the tanks was 1"~1.25"... I used four 3/4" PVC U tubes... at a flow rate of 75~100 gph (actual flow rate)...

 

[nfored]

I can attest to this, I had two 55 gallon rubber maids connected via a horizontal 2" pipe at the bottom, and I can promise you this it was not able to move the water anywhere close the the max.

I also had 2 tanks same exact size, setting on the same table, with the bottom drilled with the same size hole 3/4 hooked together and then draining to a sump, the flow was greatly reduced since they where hooked together and fought the weight of water on the other side.

You can see this for your self If you have two tanks next to each other on full one empty the full one will drain to the empty one faster, then if both where half full and you dumped enough water to fill one tank up into either of the tanks.

 

[pjsmetana]

...

Not so fast there...

In the DIY there is a thread that usggests the "maximum" flow rate of different diameter pipes/hoses. But we should not foolishly assume that every pipe or hose will flow at the maximum flow rate. That chart/thread clearly explains that there is a minimum drop required to acheive the maximum flow rate.
...
In my situation photo'ed above, the functioning difference in water surfaces between the tanks was 1"~1.25"... I used four 3/4" PVC U tubes... at a flow rate of 75~100 gph (actual flow rate)...

I have a 900gph little giant pump with a 1.5inch diameter pipe... he asked what could handle 250gph and obviously a 1inch pipe can. No one asked about maximum flow rates, as that requires a formula.

 

[nfored]

Well sir pj a pump is no where near the same as a siphon. BTW my little giant 1000gph pump used 3/4 or .5 pipe which ever i wanted, pes-800-pw the original one not the restricted revision, so does that mean I can flow 1000 or even 800 gph though .5 pvc?

That pump was put 5 feet below the tank and a single 1" diy pvc over flow which had a 3 foot drop couldn't keep up with it? so what does that mean?

 

[pjsmetana]

...
That pump was put 5 feet below the tank and a single 1" diy pvc over flow which had a 3 foot drop couldn't keep up with it? so what does that mean?

As Tim "the tool man" Taylor would say, and MFK in general... MORE POWER arr arr arrr! If at 1st you don't succeed, try it again, but this time go bigger.

 

[nfored]

That pump at that hight was just under 300gph so a pvc overflow at 1" with a 3 foot drop and no back pressure was getting 250ish when clean.

So in his setup not only is there little or no drop there is back pressure on both ends so that means he likely wont get any where close to 250gph. We tell the OP this so he doesn't have a flood.

 

[Brewster320]

So basically I would need.....? Lol

 

[nfored]

You know what might work and look sick, if the tanks and fish can fit it, is a water bridge.

 

[Brewster320]

You know what might work and look sick, if the tanks and fish can fit it, is a water bridge.

That would look but one tank is for guppies and mollies and the other in a snapping turtle... So that probably wouldn't go over very well lol

 

[Toby_H]

he asked what could handle 250gph and obviously a 1inch pipe can.

Don't be so quick to misdirect people with your assumption. A 1" diameter pipe/hose will not allow 250 gph to siphon through it when two bodies of water are within an inch or two of the same surface elevation.

I posted personal experience at length above to give the OP a solid idea of what he could expect.

In my situation photo'ed above, the functioning difference in water surfaces between the tanks was 1"~1.25"... I used four 3/4" PVC U tubes... at a flow rate of 75~100 gph (actual flow rate)...

I used 4x 3/4" PVC U tubes (area = 1.767 sq.in.) to move 75~100 gph and the water level of the tank rose 1~1.25"... If the OP were to use a single 1" PVC U tube (area = 0.785 sq.in.) to move 250 gph I would expect the water level of the tank to rise several inches...

This may work for the OP's plan, as the water level in the turtles tank needs to be lower than the water level in the planted tank. I feel this idea is worth exploring, but it's important to have a general idea of what to expect when begining the experiment.