Who hates having powerheads located somewhere in your reef aquarium?
Trying to attach them to the sides of the tank so they point towards the reef structure where the current is required, and then taking up visual space?
Or attempting to hide them behind rocks somewhere around the back but then loose the amount of current the corals feel?
Plus then have a large hassle to remove the pump or maintenence?
Well, here is an idea that might help to minimise all of these problems using external circulation pumps.
Initially when I set up OZ REEF the in tank water circulation consisted dominantly of two Eheim 1060s mounted on top of the tank.
The inlets were Hagen Aquaclear Quickfilter Attachments on the end of PVC piping, while the outlet was vinyl tubing ending in barbed elbows.
The outlets were held to the glass by heater suction cups along the left and right ends of the tank.
And it worked very well, not taking up much visual space, very little space in the tank, and the current was going where it is needed.
But I was not entirely happy with it, especially those heater suction cups which just do not go the distance.
Eventually they would loose their strength, letting go at will and messing up the water movement or blowing the sand around as it drops down.
Cleaning them helped to lengthen their lifetime, but not for all that much longer.
What you are going to see here is what I have updated this to, in what I believe is one of the best ways to circulate water in an aquarium using pumps, solving all of the last major problems.
And so far things are working very well.
This new system follows the same principles of that of the original, but with some very important improvements.
Below is a diagram showing how it works and the arrangement of the various components.
The diagram shows the approximate layout of the left hand circulation pump, and it is repeated for the right hand side.
Water circulation system diagram, the horizontal blue line represents the water surface.
Lets start with the prefilter, which consists of a Hagen Aquaclear Quickfilter Attachment.
These are perfect as a pump prefilter, after the sponge has been removed.
The water flow is distributed over a large area and the slits are narrow enough so that any "large" organisms can't be sucked into the pump, and wide enough so they do not become clogged.
The original prefilters are still in use and over the last 2 years have become heavily encrusted in coralline algae, to no detrement to the flow through it.
They also make the perfect home for vermitid snails, those the live in tubes cemented to the surface and feed via a mucus net.
This is glued to some 25mm PVC piping, the ends of which have to be filed down to fit into the prefilter, but can be quite easily removed if there is a need via a very simply to use twist locking system in the prefilter.
On the end of the pipe is two 45o elbows to change the pipe direction from vertical to horizontal.
Two 45o bends are used as there is less pressure drop across them compared to one 90o and it gives a chance for the piping to avoid the lighting hood that is hanging over the top of the tank.
If it went straight up and out of the tank, then through a 90o elbow the pipe would hit the hood.
Then there is a 90o elbow, something that would have been good to avoid but space is limiting to change the pipes direction in.
The challenge with having external circulation loops like this is the fact that if the lines are full of air then they have to be primed with water before the pumps will operate.
Until now I have done this by linking the outlet from another pump to the outlet of the circulation loop and forcing enough air out to start the pumps operating.
It is not difficult to do in itself, but there is a much easier way to do it and it can be a bit fiddly.
Simply place some airling into the intake side of the pump and use a check valve that only allows air to be withdrawn.
All it then entails to prime the pump is to suck the air out of the intake side through the airline until some water starts to come out the airline.
Once that is done the pump can be started and air does not return through the pump due to the check valve.
And if you are worried about what happens when the power goes off, well nothing happens, both ends of the loop are under water so no air enters and it does not require repriming.
Next a union joint is used to make it very easy to pull apart and ensure that there is no undue stress placed on the pump inlet while aligning and attaching the piping.
Then comes the pipe reducer to the pump inlet thread size.
Note that both the inlet and outlet sides of the pump were increased to the next size piping to reduce the frictional losses, which will then inturn mean there will be a higher flowrate out of the pump.
So the inlet went from 19mm at the pump to 25mm, and the outlet from 13mm to 19mm piping.
See the following photograph showing the PVC fittings used on inlet side and the outlet assembly.
Center bottom is the outlet consisting of two male to female 19mm PVC elbows. Across the frame is the inlet to the pump minus the prefilter, with the union join to the left. Eminating from the 90o elbow is the air line with check valve.
Now the outlet side starts with a 19mm barb to 13mm thread from the pump, aimming directly upwards, with a short length of about 60cm of 19mm vinyl tubing.
Vinyl tubing is used so that there is a gradual curve between the pump and the rigid final outlet section, flexibility allowing the outlet pipe to be twisted and raised up and down as required.
The outlet line is then converted to 19mm PVC piping, which is now horizontal.
To get the piping vertical and down into the tank, two 45o elbows are used, once again to reduce frictional losses.
The pipe is now vertical, and the length used allows the pipe to go to down to about 2/3rds of the depth of the tank.
The pipe is then held to the tank canopy by a simple clamping bracket.
It consists of a horizontal length of wood that has three holes large enough for the 19mm pipe to fit through drilled in it.
The reason for the three holes is so that front to back location of the outlet can be adjusted with some degree.
A simple clamp then holds the pipe in place so that it does not move or vibrate.
View under the lighting hood of the inlet for two circulation pumps, have changed it so two Ehiem 1060s draw through the same inlet.
Top view of the three circulation pumps that are now part of the circulation system, 1 x PM-4200 and 2 x Ehiem 1060.
And now for the most important and flexible part of the entire setup, the outlet.
This consists of two 90o PVC elbows that are male to female, which means one slips on the end of the piping, then the next one on to the first forming a double joint.
If they are not glued into place then it is possible to rotate each through 180o, giving total control over the direction the water flows in.
The outlet consists of two male to female 19mm PVC elbows on the end of 19mm PVC piping. They are not glued on so can be rotated 360o in the vertical and horizontal planes. (note image is slightly distorted due to angle through the glass)
Righthand outlet after several years in the aquarium, covered with vermetid snails and coralline algae.
This is how the outlets are mounted in the tank, right hand side. The vinyl tubing from the pump is up upper left, into the two 45o elbows. The clamp holding the piping is place is 1/3 of the way down from the top of the frame, with two "eyes" that are the bolts used to tighten the clamp. Piping below the water level is showing coralline algae growth, the dark blotches.
And that is all that is to it, very simply.
Pumps do not take up space inside the display tank, heat from the pump is reduced, ease of positioning of the outlet and full directional control over the outlet.
The following is a list of the parts used in this instance roughly in order from the inlet to outlet, note this list is for 2 systems.
2 x Hagen Aquaclear Quickfilter Attachment
These are the prefilters for the pump inlets, sponges removed.
50cm x 25mm PVC Pipe
For the inlet side of the pumps to run between the various fittings from the prefilter to the pump.
4 x 25mm 45o PVC Elbows
For the inlet side of the pumps, used to keep out of the way of the lighting hood and minimise the pressure drop.
2 x 25mm 90 PVC Elbows
For the inlet side of the pumps, to align the piping with the pump inlet.
2 x Airline Joiners
To be glued into the inlet line to allow priming of the pumps.
2 x Air Check Valves
Stop air from being sucked back into the inlet line and through the pump.
50cm x Airline
Long enough so that can be reached easily to prime the pumps.
2 x 25mm PVC Union Joints
Allow easy disconnection of the pumps and reduce stress on the pump inlet lock.
2 x 25mm Slip to 19mm Threaded PVC Joint
Reduce the inlet pipe to the Ehiem 1060 pump inlet size.
2 x 13mm Threaded to 19mm Barb
Allow connection of the pumps to vinyl tubing.
1m x 19mm Vinyl Tubing
Run the pump outlet to the outlet PVC pipes.
2 x 19mm Threaded to 19mm Barb
Connect the vinyl tubing to PVC pipe.
2 x 19mm Threaded to Slip Joint
Connect barb to PVC piping
2m x 19mm PVC Piping
To extend the outlet down into the water and connect the other various joints together.
4 x 19mm 45o PVC Joints
Change the angle of the piping to vertical and minimise the amount of pressure frop
4 x 19mm 90o Male to Female Slip Joints
The directing head of the outlet, these are not glued into place but left free so that the outlet direction can be changed with ease.
Comments
Written by Ruhi on 2006-09-13 16:21:51Thanks for sharing the project. I wonder though if one couldn't do this by just simply making return from sump/filter atached to "outlet" instead of adding another pump and plumbing.
Re: Written by
on 2006-09-13 16:24:05Yes, you could do that.
However, you are not adding any more circulation to the tank, it is still just that of the return pump, which is insufficient for a typical reef tank. You add a circulation system like this to increase the amount of water circulation within the tank.
The idea that most people are using now is to have holes drilled through the side or base of the tank, and have the inlets/outlets plumbed through there to give the closed loop circulation system.
Mr Written by
on 2007-01-11 12:55:17Thanks for this and your lighting hood and canopy articles. I am a newbie just about to make some decisions about which way to go with lighting and circulation in particular. It was great to see such practical information. A couple of questions if I may
1 are the circulation pumps above the water or do they stick out the back on a shelf?
2 Are the pumps noisy at all - not being shut in a cupboard under the tank with the sump and other stuff?
3 Do you have a cover over the tank to stop "things" jumping out - or is this not a problem?
Thanks again anyway for some real help.
Re: Mr Written by
on 2007-01-11 12:58:391 - yes the pumps are above the water surface. They are also actually behind the tank itself, sitting on the shelf I built into the hood to hold them. This means they do not take any room up above the tank itself, which is actually used up by lighting.
2 - no, they aren't as they are Eheims, very quiet. And note being in a cupboard will not necessarily make a more noisy pump quiet, you get real issues with vibration and reverberation.
3 - no I don't, but don't need to as there is no easy way for a fish to jump up and actually get out of the tank. The hood fully encloses the top of the tank around the edges directly above the tank.
Written by
on 2007-01-30 09:36:02I built a closed-loop with a wave-making device (essentially, what's in the article, except a little different), I've discovered that the pump should be slightly under the water level. This makes priming it much easier (use a turkey baster or small pump to force water into the system, and turn it on). But, also, even the good pumps are going to eventually leak saltwater onto everything. It might not be the first time you assemble it and turn it on. But, if you clean the pump every year or so, you're going to eventually find a leak when you put it back together. And, when I swapped it out with the pump in the sump, I discovered that the second one had a leak, too. I had just never noticed because it's submerged.
Which pump? Written by
on 2007-05-31 15:24:25I cannot find a Ehiem 1060 pump. Is this the the right model? How many G.P.M is this pump? Thanks
Re: Which pump? Written by
on 2007-05-31 15:26:08That is because that is an old model number that Ehiem use to us. They did some changes to it a number of years ago and the 10## series pumps turned into 12## series. So look for the 1260, as that it what the 1060 or its equivalent is now called.
Wavemaker/flow for reef tank Written by
on 2007-08-11 05:11:34I recently set up a 180 gal reef tank and intend to keep SPS corals. I have 2- 1225 gal return pumps from the sump...one through a SQWD and the other through a Sea Swirl. I have also built a 5.5 gal Borneman surge tank using 1.5" pipe. I want to add more flow but want it to be random surges instead of laminar. I considered another Borneman device, but there is the ever present bubble problem associated with it (and other designs). I don't want the tank cluttered up with powerheads either. Here is my thought...place a 5.5 gal acrylic tank somewhere on the side/back of the main tank so that the edge of the smaller tank is even or slightly higher than the main tank. Using 1.5" to 2" pipe, build a U tube so that a siphon can be established between the two tanks...water level should equalize. I would put a strainer on the end that goes in the main tank to protect unsuspecting inverts. Several powerheads could then be placed in the smaller tank with their outputs plumbed to the main tank in whatever flow pattern was desired. I have found that a MaxiJet powerhead is a perfect tight fit into 1/2" CPVC pipe. The powerheads could be run from a wavemaker device to alternate their flow and the large siphon would keep water levels up in the smaller tank. This would allow the powerheads to run submerged so it would not matter if they leaked...and they will eventually. This should function with no bubbles added to the main tank as the output lines would always be full of water after the initial startup. I have not built this yet so please do not hesitate to take shots at the idea. If you can point out why it won't work or why it's a bad idea, it will save me time and money. The only maintenance I see with this system would be the occasional cleaning of the intake strainer and replacement of powerheads as they die of old age.
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