Need some help with my skimmer.. pics

[One_Divided]

This is a DIY Hot-1/airstone style skimmer.. I am having a little trouble getting the collection cup down.. foam production and the return are fine from what I can tell and I am not losing bubbles. I am having a little trouble figuring out the best dimentions for the collection cup.. right now, foam makes it up to the top of the cup tube sometimes, but doesn't quite seep over. It just bubbles at the top and then dies down.

Would it help to shorten the tube between the reaction chamber and the collection cup? Or should I make the diameter of the tube smaller.. I originally wanted it to be 2 inch, but I couldn't find any in town and thought 2.5" would work.

Or should I try lengthening the inside cup tube so that the foam hits the top of the collection cup and spills down? Similar to a remora hang on..

Thanks in advance for any help!

http://livevictoria.com/limestone/reef/skimmer03.jpg

Photos:

http://livevictoria.com/limestone/reef/skimmer01.jpg
http://livevictoria.com/limestone/reef/skimmer02.jpg

Sorry for the rough diagram.. I forgot to mention that the reaction tube is 4" acrylic.

[ 23 December 2001: Message edited by: One_Divided ]

[reefburnaby]

Hi,

Do you have a valve on the input or output that allows you to adjust the level of the water ?

- Victor.

[titus]

Hello,

You'll notice that larger skimmers designed for larger loads will have a longer and wider neck. This is because a large system will have enough waste to be pushed up such a long and wide neck without being too wet by the time it is collected. However, using the same skimmer on a small tank would mean it's gonna take a lot longer for the waste to reach the cup to be collected. So bottom line, try to make something that would work with your existing system. This is really a judgement call here.

[SuperFudge]

Hi Guys,

That size of riser tube should work fine,on the few ive built in the past of similar design i found these types needed the most time to break in....
I think its becuase of the hieght of the injector where NEW tank water is being injected into the reaction tube,it has some effect on the bubbles that have already risen from the bottom....maybe being stripped of organics when they pass by the injector??
I found that it still worked fine,but seemed to need a few days after initial start up and after cleaning,before it really showed its merit.

I think your size of riser tube is fine,but i also think you are right,it may be better to have the riser extend to within 3/4" to 1/2" from the bottom of the cap....to keep from letting foam build up any back pressure and working against itself.

If you have any rubber couplers that would fit that outside diam,you can play with the hieght a bit before making any permanent mods to it.

Also,try making the out put tube(on the outside of the skimmer) at just shy(say 1") of the height of the water level you desire inside the chamber...before it can spill over into your sump...then you can reduce the water entering the skimmer more without it changing the water level.(this also was a big factor in getting it to work right....i had to slow down the water quite a bit without losing water hieght.)
And at the spill over point,do not put and elbow and pipe facing down twords your sump...this creats a siphon,you can place a tee at that point with a small length of pipe facing up(a breather),to avoid siphon trouble.

All in all,i think it looks like it should work fine....try giving it a few days and see what she does !

Merry Christmas guys,
Marc.

[ 24 December 2001: Message edited by: Fudge ]

[DJ88]

Hey Adam,

It's not that you need to lower the collection cup. You need to raise the water level.
To do this you will need to do a few things(not all just some). Especially since you are putting it in a sump and not hanging it.

<UL TYPE=SQUARE>

<LI>Increase pump size. You said RVT. is it a 800 or 600? You may need to go bigger than a MJ1200 even...

<LI>Put a ball valve on the output so you can adjust the water flow OUT of the skimkmer. This raises the water level within the skimmer.

<LI>Add a second airstone being driven by an independant air pump to increase foam production.

<LI>Move the input from the RVT up higher. This will raise the water level.

<LI>If anything I would make the neck longer. 6 to 8 inches. Use this thinner area for the actual foam production. Have your water level within this neck(five or six inches below the bottom of the collection cup). By having the foam have to go past a change in diameter a lot of the bubbles will break and you lose the pressure of all the bubbles pushing the ones on top up and out of the skimmer.

[/list]

The two I would do for sure is make the neck longer, much longer and add a ball valve. This is important as it lets you control the water level in the skimmer. Without this you are at the mercy of your pump and how fast the water leaves the skimmer for the water level. The others will help get a higher water level(pump) and increase bubbles(drier foam due to lower water level needed to get foam spilling over the lip of the neck.

Do that and your skimmer should work better.

As well make sure that at the spots where you get a change in diameter of the tubing, the edges are very very smooth and rounded. Sharp edges will cause premature breakage of bubbles.

[ 24 December 2001: Message edited by: DJ88 ]

[One_Divided]

WOW! thanks a lot guys!

It's hard to see in the photos, but there is a ball valve on the return.

The Pump is a Rio 800 RVT. I will try a mj1200.. I do have a couple spare right now.

I originally had the riser tube 4 inches and recently cut it way down.. I wanted it spaced so that the riser tube carried mostly only bubbles and not so much water.. But I guess you are right Darren, if I had more foam I could get away with a longer riser tube.. I will try another airstone soon..

I'll take a couple pictures of it running and post them shortly.. This skimmer is mostly just a test for me.. I don't even know what I want to use it for.. If I find it beats out my remora, it may be replaced

thanks again for all of the good advice everyone!

[One_Divided]

More photos:
http://livevictoria.com/limestone/reef/skimmer04.jpg
http://livevictoria.com/limestone/reef/skimmer05.jpg

[ 24 December 2001: Message edited by: One_Divided ]

[DJ88]

In that case this is what I would do.

Ball valve(done), larger pump.. mag 2 or more, smaller PVC tubing to restrict flow even more(if using a MJ1200), second air stone.

Add a small mag and throttle it back. Increase your neck length to allow for more adjustability.. You will find that as it gets used you will need that adjustment capability.. especially if the flow out gets restricted slightly due to growth inside the tubing.


FYI.

The HOT1's work because they are kept at the water level of the tank or sump. This makes for less work on the pump less than 6 inches vice over a foot as you have it now. As an insump mudel you will need to add a much more powerful pump than a MJ or Rio 800. they lose too much GPH at that distance. Once they lose that much GPH they will not be running your skimmer efficiently. Your flow into and out of the skimmer will be so low that it is doing next to nothing.

If you wanted to do this over I'd recommend using a taller reaction chamber(say 24") a much larger pump and inject the water so it spirals up the column from lower in the chamber. I'll draw a pic when I get home.. dont have any software here to help ya.

[maimz]

..im also doing up a diy skimmmer....i pretty much think that i have things under control as far as design goes..but im unsure on how powerful of an injection i should have when pushing water into the skimmer.i mean i am figuring that i could probably get away with an airlift design but i am unsure if that will pump enough into the skimmer as i dont know how crucial this part of the design is to the functionality of my skimmer..and as well the main thing holding me back is at what height i should inject the water into the skimmer in relation to the distance from my airstone as well as the distance from the collection cup..any suggestions will be great..merry christmas.

[DJ88]

maimz and Adam,

You want to have your water incontact with teh bubbles for as long a period of time as possible. So put your water injection fairly high up. The water flow should be slow enough to allow good contact but not too slow. There is a happy medium.

take a read of the skimmer DIY (http://www.hawkfish.org/snailman/snailmandiy.htm) links for some good reading.. Hopefully these will give you some answers. read the theory before looking at the design aspects. This will answer the pump size, turnover rates, how high for water injection etc.

Good reading..

[ 25 December 2001: Message edited by: DJ88 ]

[DJ88]

FYI

In the theory links you will see that it is recommended to have a CC skimmer at least 28 to 32 inches in height for it to function properly unless for VERY SMALL aquariums.

These recommendations come from books published on skimmer theory, operation and design..

Just so you know.

[ 25 December 2001: Message edited by: DJ88 ]

[One_Divided]

I looked at the general specs on the precision marine page when I made my skimmer.. Not that I disagree (I know next to nothing on building skimmers), but if the precision marine airstone model works; why not go 18"? Obviously longer contact time will be better, but damn acryilic tubing is expensive! lol.. I would think that the small bubbles produced from the airstones would make up for that to some degree with more surface area.

Look at the specs here (http://precisionmarine.com/Air_Powered_Series/AP426/ap426.html)

[DJ88]

Well from the work I have done with Skimmers I would say that the skimmer PM makes is only good on a smaller size tank. Most CC skimmers I have seen for larger systems are well over 32 inches high. Even up to 6' high for something on a 150 gallon system. For the most part take the manufacturers number with a grain of salt.. I usually take it down by about 50% on venturi and airstone skimmers. Those are numbers I have seen with a bit of research into skimmers of various designs. Bullet(beckett) styles usually are close to the mark as they are forced water and air production. Different from venturi and CC air stone skimmers.

Most air skimmers use those same wooden airstones for bubble production, so you will probably get the same bubble production as others.

The PM systems offset the height by having the water rotating in the column to allow for more contact time. Same idea as the Venturi skimmer they make. If you look you will see that the injector is offset from center to give it that swirling motion. With the PM site you will also notice they don't give a recommended water pump.. I'd say you will need something more than a MJ or Rio 800 on it.

Just some helpful words.. If you are putting this on your tank you may want to take others experiences such as snailman's.

IMO you will end up with a skimmer that isn't strong enough for a tank your size. I ran a CC skimmer on my 90 for a while and the only height I found worked half decent was a 5 foot tall skimmer. With two air stones and a massive pump driving those. You will also find that they only work for a while then you need to replace the stones. Once a month is a good rule of thumb. For water flow I had a hagen 5000 on it pushing 1000GPH. I think mine didn't work that well as I didn't have a strong enough air pump on it. You will need a huge air pump to run a tall skimmer efficiently. If I remember right I priced some out at over $150 each with enough pressure and able to handle the back pressure.

HTH

IMO IME

[ 25 December 2001: Message edited by: DJ88 ]

[One_Divided]

Darren, next time I venture in to doing something like this, I'll have to chat with you first! lol

Well I have the skimmer working pretty well now. Next time I do it, the intake will be offset.. Also, I may still make the riser tube longer again.. As you can see that I need in this pic.. And I think for a biger system, a longer reaction tube.

All I did to kick start the skimmer is drop the skimate in from my remora to give more to skim.. In about 5 minutes, this was the result.. I did a turkey baster analysis (lol) and I could see the the skimate is almost black and the water in the bucket is clear.

Are there any precautions that I should take before testing it on my main tank? I can't imagine toxic glues are good.. do I need to soak it or anything? images/smiles/icon_eek.gif


http://livevictoria.com/limestone/reef/skimmer06.jpg

[ 25 December 2001: Message edited by: One_Divided ]

[DJ88]

What kind of glue did you use Adam?

Weld On works the best. It actually fuses the acrylic together at a molecular level.. images/smiles/icon_smile.gif So I am told. . images/smiles/icon_wink.gif

If you raise that water level up it will work wonders.. images/smiles/icon_smile.gif

It's all a learning experience.. images/smiles/icon_smile.gif

After I was hurt and not able to work I had all kinds of free time on my hands.. So I built skimmers and researched them.. images/smiles/icon_smile.gif

[One_Divided]

I used the weld on stuff in addition to methol hydrate (is that right?). And I siliconed the crucial areas..

raising the water level at the point I took that photo would have just shot the foam to the roof lol. I had to crank it was down when I added the skimmate.. it's up again..


thanks again everyone and marry x-mas!

[DJ88]

All you ned is Weld On.. lol

A good bead of this seals it completely..

Good to be thorough tho..

[One_Divided]

heheh.. just want to be safe on my first creation..

So do you think it would be safe to run on my system at this point?

(we're busy this christmas!!... really! right darren? ) images/smiles/icon_wink.gif lol

[DJ88]

How long did you let it sit and dry before adding water? that is the question.. The weld on can be immersed pretty quick after drying.. Longer the better tho for a good bond. Overnight is a good rule of thumb I follow.

[terryp01]

I always wait 24 hours on the weldon. This allows the bond to cure and strenghten so you don't have any water blowing under your tank. Trust me on that one, I learned the hard way.

[One_Divided]

All welds had at least 24 hours accept for one at the top of the riser tube.. it only had a couple hours before I ran it with water again.. anxious!

[maimz]

..noticed someone mentioning that they didnt find the gunk to move into the "overflow cap" that easily...i have read that the reason the foam is pushed up through the top is because of the temperature difference that is above the water level...therefore im assuming that the more drastic this difference is would equate to the speed of the foam moving up into the overflow at a higher rate...just a thought...its all very interesting..

also.. www.aquaticeco.com (http://www.aquaticeco.com) is the best..i am thinking of becoming an agent for them and that means cheaper shipping..they sell all the acrylic tubing there as well as the industries best quality air diffusers that are made from heat bonded silica..the model that i think woudl work best is the AS40 ..i will be using these on the skimmer that i am making in the near future..peace