My DIY skimmer...PIC INTENSIVE...

[bobn4burton]

Hi all,

I decided to build me a skimmer. This is the first skimmer I've ever built and even the first "real" skimmer I've owned. I took my ideas from several sources (Euroreef, deltec, other DIY'ers, my own brainstorming). I'll list some quick specs of the skimmer and then show a bunch of pictures of the whole build process (I'm showing a ton of pictures because I always like to see lots of peoples pictures...so if you don't want to see all the pictures then just scroll to the end )

Skimmer Specs:

Reaction body: 6" extruded acrylic tubing 18" tall
Pump: Ocean Runner 2700 (2700=2500+needlewheel impeller)
Air intake: DIY venturi on Recirculating pump
Riser tube: 2.75" riser tube about 3.5" tall
Skimmer total height: 25" tall

OK, now on to the pictures...

This first picture is one of all my supplies before getting started:

I decided that I wanted a slanted skimmer neck to transition from skimmer body to riser tube. This should help with bubble travel from body to riser. To do this I simply heat up a disc of acrylic in the kitchen oven and formed my reducer.

Here are two pieces of plywood I used to sandwich the acrylic while heating:

You can see the 5.75" holes I cut in the plywood for the forms. This next picture shows the acrylic "sandwich" cooking in the oven:

I then used the tubing reserved for my riser tube to push the acrylic into my shape as seen below:

Here is a picture of the finished reducer after thermo-forming:

I then cut a hole in the thermo-formed reducer and glued my riser tube on:

I then started working on the body. Here shows the holes in the body for pipe inlets/outlets:

And this pic shows the flange used to fasten the collection cup assembly to the body being glued to the body:

 

[bobn4burton]

The next part that I worked on was the ventui. It was quite simple really, just an airtube pushed tightly into a Tee with a hole cut in the airtube for air to be pulled into the water stream and into the pump.

Here are a couple pics of the venturi:

I then worked on the collection cup and keyholes to fasten the collection cup assembly to the body. Here are a few pics of the process:

Now all the parts were about done. I actually flipped the pump backwards from the way you'd normally see the deltec or ER recirculating skimmers. This gave me better airflow into the body because the venturi inlet was a good 4-5 inches higher and so it had less backpressure on it. Here is a pic of the mounted pump:

And finally here is a pic of the finished product:

 

[bobn4burton]

And a couple shots when I was testing it in a tub of tankwater:

These two foaming pics were taken immediately into the testing. After running it for two days straight the skimmer started to "break-in" a little and it was actually foaming about 3 times as good but I didn't get pics of it then




Oh...and just as FYI...here is a pic showing how the pump would be mounted "normally" in the deltec or ER fashion. I can switch between either mounting position within seconds...so its nice to have either option. But I found that my method with the "inverted" pump pulls the most air.

 

[elpezpr]

You are an artist. If I could do that....

 

[shouldabenacowboy]

Nice job!!....Keep us posted on progress

 

[Horace]

Ok so I understand the idea of the recirculating pump there, and the drain out, however where does the water enter the chamber? Through the top inlet that doesnt have anything hooked to it??

Is the inlet to your skimmer hooked directly to the drain on your tank and gravity fed in there?? Seems that would be a good idea if thats what you did. Thus the pump would be used exclusively for creating bubbles and can be going at a very high pace even though the actual water flow is not that fast....Ideas are goign through my head now

I am currently finishing my DIY skimmer as well and this design may change my design a bit...I wasnt fully aware how the recirculating skimmers worked but this makes perfect sense to me now.

 

[Bugs]

Did you cut the acrylic yourself or you ordered pre-made? If you cut it yourself, how do you cut the outer circle and the inner circle? Very nicely done and creative.

What would be the cost and time spend making your own skimmer? Where did you order all your parts? It must be very time consumming to get all the parts. I have difficult time getting the fitting for my calcium reactor..... GOOD JOB!!!

 

[MK Reefer]

Wow, If I put that in my oven I would be out in the cold as my GF would throw me out hehehe

At what temp does acrylic melt? that is a real interesting idea on how to make stuff...

Mike

 

[Rendos]

Looks good. How loud is the venturi? I made myself one the other day and it sounds like a freight train. Maybe I did something wrong.

 

[bobn4burton]

Ok so I understand the idea of the recirculating pump there, and the drain out, however where does the water enter the chamber? Through the top inlet that doesnt have anything hooked to it??

Is the inlet to your skimmer hooked directly to the drain on your tank and gravity fed in there??

Yes...the water will enter the pipe with nothing hooked to it right above the pump. I just haven't hooked it up to my tank yet...so that's why its not hooked up. I will just be feed it from the drain of my display tank to save some $$ on an extra unecessary pump.

Did you cut the acrylic yourself or you ordered pre-made? If you cut it yourself, how do you cut the outer circle and the inner circle?

What would be the cost and time spend making your own skimmer? Where did you order all your parts? It must be very time consumming to get all the parts. I have difficult time getting the fitting for my calcium reactor..... GOOD JOB!!!

I had some pre-cut and some I did myself. I just got all the acrylic from a local plastic shop. They cut the 6" tubes to the right lengths, all the circles I used. I had to cut all the holes myself with a hole saw. I also cut the inside circle out of my 9" disc to make the ring with just a jigsaw.

I spent about 130 dollars total including OR2700 pump which was 50. It took me a full day to complete the project. It would go quicker if I were to do it again because a lot of that time was spent designing/planning.

I got all the acrylic from a local shop (was cheaper than online even). I got all my pvc fittings from homedepot and the telescoping piece from a local plumbing store.

At what temp does acrylic melt?

I heated it to 300 deg F. It was just the perfect amount of plyable for me at this temp. As has been discussed on this forum already, be warned that there is a possibility of toxic/flammable gasses escaping the acrylic while heating and so if you heat it in your kitchen oven like I did then there is some risk there!

How loud is the venturi? I made myself one the other day and it sounds like a freight train. Maybe I did something wrong.

Well, its hard to say because I don't have any experience with any other venturi except this one that I made. It is pretty loud if you don't cover/muffle the end of the airtube. But I will probably be restricting the airflow a little anyway because it pulls so much air that my OR2700 is right on the verge of cavitating. Once I restrict the airflow down a little it is much quieter. Then the only noise I hear is from the needlewheel chopping up the bubbles. But I noticed that it helps a lot to submerge the pump for this problem.

 

[fishfood2581]

why did you do all that crazy plumbing to the pump intake? why not just turn the pump over?

 

[SHOmuchFUN]

That skimmer essentially has no neck?
Isn't that going to make it hard to control foam consistency? I mean, to me, it looks like you're going to either be pulling wet foam, or nothing at all

 

[sWampy]

I think you have given me a new project to try this weekend.

 

[bobn4burton]

That skimmer essentially has no neck?
Isn't that going to make it hard to control foam consistency? I mean, to me, it looks like you're going to either be pulling wet foam, or nothing at all

The neck/riser is a little on the shorter side of those out there. However, it isn't too far off from the ASM skimmers. Mine looks a touch shorter too because I used my reducer as the bottom of my collection cup. So my collection cup is actually 6" tall which is 1 to 2 inches taller than most collection cups on similarly sized skimmers. I just couldn't see putting another piece of acrylic on there when I could use my reducer piece as the bottom of the collection cup.

I think it will work good for me for two reasons. I have real good control of water level inside the skimmer because of the telescoping output. I'm not fond of using a gate/ball valve to control the water height in the skimmer because it seems less accurate and more risky. Also, I plan on skimming a bit on the wet side as it is anyway because I'm leaning towards going the BareBottom route and it is usually reccommended to skim fairly wet with BB.

 

[ejamsrhere]

I wonder if inverting the pump would make a difference in a 6' skimmer....


I'm not exactly sure why that works. If it's plumbed recirc... there shouldn't really be any head pressure on it. I wonder if it's just restricting the input to the pump - making the pump pull more air.

 

[bobn4burton]

I wonder if inverting the pump would make a difference in a 6' skimmer....


I'm not exactly sure why that works. If it's plumbed recirc... there shouldn't really be any head pressure on it. I wonder if it's just restricting the input to the pump - making the pump pull more air.

I didn't get a masters degree in plumbing...so I could be off, but this is how I understand it.

You would be right except for one fact...this is NOT a true recirculating/closed loop system. As any recirculating skimmer (Deltec/Euroreef/whatever) is not a TRUE closed loop. The reason for this is because of the venturi air inlet. This little hole allows air to enter the closed loop...therefore making it NOT a closed loop anymore.

An easy test to illustrate what I mean is to just turn your recirc pump off. As soon as you do this...water will run up your airline until its equal height with the rest of the water in the skimmer. The higher the water level in the skimmer is...the more pressure there is at the venturi air inlet. So if you where to close the airline off and then turn the recirc pump off and compare the pressure inside the airtube to that of the air outside the airtube...you'd find the air inside the airtube to be under more pressure because of the weight of the water compressing the air.

So with that explanation in mind. The higher up I place the venturi...the less pressure the venturi has to overcome before it'll actually create a lower pressure than the atmosphere and hence start pulling in air (or rather having the higher pressure of the atmosphere PUSH air into the venturi...the chicken or the egg :rollface: ). So the higher you get the venturi air inlet the more effective the venturi will be EVEN on recirculating skimmers!!

**EDIT**
In fact, if you where to put the venturi inlet HIGHER than the water level in the skimmer...then you'd actually be naturally pulling in air without even any venturi action in the first place. The possible downside to raising the venturi higher and higher is that you have to pull all that air down the length of the tube...and as air tries to go up in water you might start running into problems trying to pull all your air down long lengths of pipe. Not sure about this last possible downside part...just thinking.

Feel free to correct me anyone if I'm way off base on this.

 

[mickey57]

...Great looking skimmer bobn4burton.
....Guys,I found out by accident,that you can just put an airstone at the end of the venturi hose.That quitened mine down so as I can't hear it.Of course,I am old and m hearing is going bad
..........................Mickey

 

[Medicine Man]

What a great job!! I have the same pump (OR 2700) and put an Optima air pump to my venturi inlet. The plus side to this is I am able to control the amount of air into the venturi via the "Rheostat" dial. In fact the Optima air pump can push so much air it will cavitate the OR 2700 pump. One thing that I have noticed with the OR 2700 is the right amount of air intake is crucial to the size and amount of bubbles that it will produce. When it is set right it produces a ton of tiny bubbles. Hope this helps somebody!

Forgot to mention, this makes the venturi silent also!!

 

[ejamsrhere]

ok... so.... hmmm..... If you have a pump plumbed recirc or just straight in, they both have the same head pressure... right? I must have way too much head pressure for my sedra 5k on my 6' skimmer... poo.

 

[SHOmuchFUN]

You have a sedra 5k on a 6' skimmer??? :eek1: