Downdraft skimmer update.

[dugg]

I know i have posted about this skimmer before, but now i am actually using one, and it really is the best skimmer i have ever seen bar none. I'm not trying to get you all to order from Wayne, although i'm sure he wouldn't mind, but this is one anyone can make for 10 bucks.It is absolutly quiet, and is making an unbelievable amount of skimmate, without pulling out a ton of water with it. I set this up on my new system ( using my previous tank water for the set up, only added 10 gallons ) on July 6th around 9pm. Here is what it has done in only 5 days of operation.

That is a 1 gallon jug, so close to a pint of good dark skimmate in the frist 5 days, and i set mine up with the hose raised up a little high until i see how fast it fills the jug, so as not to have a really nasty stinky mess to clean up one morning.

 

[alphaferret]

i have followed the other thread - i love this skimmer - one ? though- wher does the water come out after being skimmed
also are there any other diagrams of this skimmer- not sure how to put it together
might have to order from wayne

 

[dugg]

The skimmer measures 10 3/4 long by 8 3/4 wide by 8 inches tall. The bottom and front panel are cut 1 1/2 inch short to create an opening in the front bottom. (marked in black in the picture below). It has 2 holes cut in opposite corners, with 2inch couplers glued over the holes. The back side (away from the opening in the bottom), just gets a coupler. The other end has a clear 2 inch diameter tube cut 6inches long, (UNGLUED) with a cap on it. The cap has a hole drilled in it to accept a piece of 1 inch o.d. tubing fitting very snug creating a seal. You control the skim rate by raising and lowering the hose. Start out at about the half way mark and adjust it from there.

If your flow doesn't create enough bubbles for it, you can place a limewood airstone inside through the front opening to add more air. It is working without the airstone now, but many people have asked about using it on a small set up, so i thought i would experiment with adding an external air source, and it is really building a thick foam head up with the added air.

It makes me sick thinking of all the money i have spent on expensive skimmers that never worked, just to find out that for $10 i can build one that out performs any i have ever owned.

 

[alphaferret]

i'm w/ you - i love diy- but most of those other skimmers are beyond my abilities- so simple- i gotta try- or buy one!-thanks for the info-alpha

 

[dugg]

After doing some testing with lower flow rates and added air to test for people wanting to know about a smaller tank, I would have to say it's not a good choice for a smaller system with less then 500gallon per hour pump size. With the lower flow it makes too many large bubbles that make noise and explodes the foam in the riser tube, preventing it from building up a good head of skim. With the higher flow rates it is silent and works great because it has enough turbulance to keep the bubbles small.
I am still playing with it though so i may find a way around the flow yet, but so far it's not looking good for small systems

 

[alphaferret]

well thanks for the update- do you think the distance between the main tank and the sump/ skimmer has an effect on it.mine used to fall 36-40 inches now it is very minimal- w/ the sump onthe same level as the tank- my 46 stands about 112 inches higher than the sump

 

[dugg]

Distance isn't the issue here. It is the turbulance inside the skimmer box. Without a high flow rate the bubbles are able to rise to the top of the box and collect into large bubbles which disturb the foam head. With the high flow rate the bubbles all stay small and churned up, and build into a real thick foam. Also the chugging sound the large bubbles make when they hit the riser tube is unbearable. When the flow rate is high and the bubbles are kept small it is almost silent.

 

[Junix]

i dont understand, how are d bubbles created? venturi? beckett? wheres the pump?

 

[dugg]

The bubbles are created in the overflow water as it falls to the sump. The only pump is the return pump that pumps the water back to the tank.

 

[dugg]

I found the fix for using this skimmer on a low flow system, and WOW this thing is now making a foam like whipped cream. I ran an airstone (limewood) and placed a powerhead inside the skimmer. This basicly reproduces the 1000 gph flowrate that a larger tank has. The powerhead is pointed at the hole where the return water enters the skimmer and breaks up the bubbles further and also churns the water real strong. I am not getting any micro bubbles in my sump at all.

 

[alphaferret]

thats what you used on the 30?
thats cool- i just got a whole bunch of acyrlic the other day-1/8 & 1/4- in both white and clear- also this other stuff the guy said was even stronger than acyrlic - but i forgot the name - i'll check when i get home late-what a deal i got too -free!!whooo hoo!
i could be my next weekend project- how often would you have to change the stone?-is that the type of stone that creates the greatest finist bubbles?- thanks for tha info!=-alpha

 

[dugg]

Yes, i am using this skimmer on my 30 gallon. It is working great. The limewood airstones last quite a while, usually 6 months or so between changes. They make the finest micro bubbles of any air diffuser that i know of. The skimmer would be very easy to make, i would think about a 1 hour project, maybe less, and cost i would think around $10 to build. IMO this skimmer works as good or better then any i have seen or used. It is really designed for a large tank with a high flow rate, but with the air and powerhead added, you can use it on small tanks too. I'm not sure of the size of my powerhead i am using, as it is a very old one, and has no labels on it, but it is a large size like a maxijet 750 or so. My only worry now is that this thing may over skim my water if that is even possible? You won't catch me complaining about it working too good though after years of fighting one skimmer after another trying to get one to actually work and stay consistent.
The person who designed this skimmer, is using one on a 140 gallon tank with a real heavy fish load, and keeping sps corals that grow like weeds.

 

[Prater]

I saw this the other day, it works great and Duggs tank looks awesome with the cement sides. Thanks for the invite Dugg...

 

[dugg]

Hey Steve, hope you found your way out of our maze the other day. I saw you by wallyworld after you left, but couldn't catch you and left my phone laying at home. You should of went straight instead of that first left to go through town lol. The streets around here are a twisted mess getting around all of the lakes. Good to see ya though, stop on by any time.

 

[Prater]

I was looking for Diesel, I took 46 instead of 44. It was a great drive by some of the lakes.

 

[brackishdude]

So basically, this is just an acrylic box with the overflow (presumably flowing turbulently in great volume from above) directed into it and exiting through a small hole in the corner, with a second outlet on top with a rigid riser tube and flexible tube drain, adjusted by pushing the drain in or out?

That is an awfully high arc on the drain tube. Seems difficult for adequate skimmate to be pushed that high using only the gravity-driven flow/microbubbles, your fantastic loooking results not withstanding.

am I missing something here?

I have seen many threads wherein folks post pics of their turbulent returns (sometimes from a full story/floor above) and wonder if there is a way to piggyback a low cost skimmer. While some posters respond, nothing more than idle suggestions are offered.

Your's (Wayne's) would seem to be an ideal solution. I found his site, but though the skimmer is mentioned (30$), there are no pics or further explanation.

Can you comment on my questions above and give a more detailed account of your experience with this skimmer?

I have a lightly brackish tank, and your comment that skimmate was produced even with all fresh water has caught my attention!

 

[dugg]

Yes, it is just an acrylic box that uses the overflow as it's turbulence and air supply. I know it looks like it's too simple to work, but it does work very good. The arc on the hose isn't really an issue, the air is resticted somewhat as it goes from the 2 inch riser, to the tube, causing a rush in the tube that acts like a vacume. the bubbles go up a ways, and then the thinner water runs back down. On about every 4th or 5th time it sucks up bubbles it will build up enough of a thick skim that it pushes through and goes in the jug as a foam log. This way it skims wet but then lets the water run back while the skim builds, then pushes it through to the jug.

Yes, it did actually work on the fresh water, but it did have rit dye in it. It took it a while. At first i didn't expect it to and iwas shocked when i came out to over a gallon of dye in the bucket i had set up just in case. It skimmed around 2 1/2 gallons out while it was fresh water. I did ad an air supply to it as the dye was pumped out, it made less and less bubbles. To get the last of it to skim out, i added some slime coat declorinator and the skimmer went nuts.

On my 287 gph system with a powerhead (maxijet 1250) and limewood air diffuser on a luft pump, i would rate it as good as anything i could buy under $300 and on a system like Wayne's with 1000 gph flow rate i would take it over anything out there. It not only skims outstanding on a big system, but it does away with a large pump in your system, that is creating heat, and costing money to buy and run. Wayne uses no powerheads or anything except one external little giant pump on his 140 gallon reef, and it runs unbelievable. It is loaded with sps, has probably 12 to 15 assorted fish and sits in full sunlight with 2 400 watt halides running 12 on 12 off, and he does a 50% waterchange once every 6 months. He gets the normal algae on the glass and lots of coraline. This thing is a virtual montipora digitata farm lol.

 

[captbunzo]

I am going to try to add something like this to my sump. It's only 10 gallons and I have very little room in the overflow chamber. However, I think I should be able to get something basic setup.

I will post details and results, etc, as I figure things out. Any suggestions?

I really like the idea of this funnel in the collection cup. Any suggestions on how I might incorporate it into this plan? Or if it is even necessary.

My thought is that it might keep the skimmer output foam more dry and result in less water loss. Of course, maybe the loss doesn't matter and I should just replace it during weekly/biweekly water changes.

Thoughts?

 

[captbunzo]

Ok. So I did some measuring and some pondering. And here is what I have so far. Please provide any possible input on these plans...

My downdraft / gravity-fed skimmer is going to fit inside the incoming water compartment of my sump. That section is sized as follows.

   Front to Back = 9.5"
   Width = 3"
   Height = 10.25"

And the last important dimension is that there are 5.5" from the front side of the drain pipe to the front edge of the return compartment. That space will be occupied with the foam riser tube, which will be made out of a 2" piece of clear plastic pipe. The drain pipe can come forward, if needed.

So, the box itself will be just big enough for the 2" pvc foam riser tube in the front, and the 1" drain tube in the back, plus a little clearance at the front and the back. And then in the back, I will have the open section at the bottom for water to flow into the sump.

Any thoughts?

 

[captbunzo]

Oh yeah. I also need to find some clear pipe and appropriate solvents to glue it together. Any suggestions? So far all I have found online is the pipe in 10" sections for $50 or so, which is much more then I need.