Ranger's Tank Journal

[SkiFletch]

Sure, the simple answers are two fold. #1 they use FANTASTIC pumps to supply the skimmers. Remember, what any pump driven skimmer pump does is draw water and air into its intake, dice the air up into fine microbubbles, push these bubbles into a reaction chamber (hopefully swirling them around), allow some to go to the top of the collection cup and have the rest of the water return to the tank (hopefully without microbubbles). It is these microbubbles that do the work. The more bubbles you have, the longer they are in your reaction chamber, and the smaller these bubbles are is the largest limiting factor on a skimmer's performance. Sice of reaction chamber is great, but if you cant make good quality bubbles in the first place, you're SOL from the beginning, make sense?

There are two ways to create these microbubbles. MOST skimmers use plain old powerheads with square impeller blades to chop up the air like this one (thank you marine depot):

Most cheap pumps just come with these basic easy to manufacture blades. Now these big clunky square blades dont chop air up into very fine bubbles, they tend to make bigger bubbles which rise faster and collect less junk on their way up. However, a coralife or aquaC model will use a needlewheel impeller which has TONS of small fins and protrusious to really chop up air like this (again, thanks marinedepot)

So, impeller design is the first reason. The second reason is discharge control. If the skimmer is to operate at its full capacity, the skimmer outlet needs a very good method of control to get the water in the reaction chamber to be at the proper height. If the skimmer outlet is restricted (by means of a valve), the back pressure in the reaction chamber increases (since the pump is still pusing), and consequently the water in the reaction chamber will rise. This means that, the point at which bubbles rise to the surface and start spreading up the neck of the collection cup will rise. If this level gets too high, too many bubbles are ejected into the cup too quickly and it overflows. If the outlet valve on the skimmer is wide open and there is no back pressure on the reaction chamber, bubbles will not break high enough in the collection cup and instead fall back into the reaction chamber (bad cause nothing is skimmed out of the water column then).

The Coralife and AquaC models have fantastic skimmer outlet valves to allow you to really tweak the point at which the bubbles crest and therefore get the skimmer operating where you want it to. Most other hang-on models do not have such as good a valve.

 

[Ranger]

I'm going crazy over this skimmer issue. Lol, im just gonna go down there and exchange it for a superskimmer. On a separate note, i was admiring my live rock today (exciting for me, lol) and I noticed some hitchikers!!! One is what I believe to be a very small clam and the others I had seen on rocks in other tanks but I don't know what they are. They are very tiny and resemble little worms with feathers coming out the top. What are these little guys? Bad? Good? Soon to be dead?

EDIT: Also, thanks for the great info ski!

 

[maidenfan]

sound like feather duster worms to me or small tube worms good filter feeders oh the joys of rock watching

 

[Ranger]

Gosh, went down to LFS today and got hassled for exchanging "what is probably the best skimmer out there for a tank [my] size". This guy is sortof a friend, so he was jerking me around on purpose in an attempt to "help" me. I got it in between classes so I haven't set it up yet, looking forward to doing that in a couple of hours though.

 

[SkiFletch]

Gosh, went down to LFS today and got hassled for exchanging "what is probably the best skimmer out there for a tank [my] size". This guy is sortof a friend, so he was jerking me around on purpose in an attempt to "help" me. I got it in between classes so I haven't set it up yet, looking forward to doing that in a couple of hours though.

Yikes, are you serious, some LFS owner has clearly not seen either of the skimmers I mentioned in action. Which one did you pick btw? Just wait till you see the amount of bubbles created in the others

 

[Ranger]

Gosh, went down to LFS today and got hassled for exchanging "what is probably the best skimmer out there for a tank [my] size". This guy is sortof a friend, so he was jerking me around on purpose in an attempt to "help" me. I got it in between classes so I haven't set it up yet, looking forward to doing that in a couple of hours though.

Yikes, are you serious, some LFS owner has clearly not seen either of the skimmers I mentioned in action. Which one did you pick btw? Just wait till you see the amount of bubbles created in the others

I got the super skimmer. You didn't tell it me was gonna be such a PITA to set up, and the pump is huge! I managed to kinda hide it though. Do you know anything about this skimmer? Cuz the water is overflowing out the top of the "bubble diffuser"

EDIT: Also I got $50 dollars extra in store credit after the exchange!

 

[SkiFletch]

Ok here goes nothing, a picture is worth a thousand words.

There's a shot of your skimmer. Now, there are 3 key things to know here. #1, the air inlet valve (bottom arrow), #2 the skimmer outlet valve (top arrow) and #3 the bubble-water interface line (blue line). So you basically want to tweak the skimmer so that there is as much air entering the pump as possible without air bubbles returning to the tank AND maintaining that air-water interface in the collection cup right where it starts to really get small.

Opening the air inlet valve will create more bubbles inside the reaction chamber. It will also decrease the height of the air water interface, and may cause bubbles to flow out of the diffuser (which should be in your tank as well). Closing the skimmer outlet valve will increase the height of the air-water interface, slow the flowrate of the pump, and possibly decrease bubbles from going back into the diffuser. Obviously doing the reverse to the valves that I just described will do the opposite things. So you need to tweak valves a little for the first week or so to get things running. On my skimmer (different brand, same features) I can open my air intake all the way. Some people cannot. I also restrict the outlet of the pump a LOT, again, some people cannot.

 

[Mr.September15]

Ok here goes nothing, a picture is worth a thousand words.

There's a shot of your skimmer. Now, there are 3 key things to know here. #1, the air inlet valve (bottom arrow), #2 the skimmer outlet valve (top arrow) and #3 the bubble-water interface line (blue line). So you basically want to tweak the skimmer so that there is as much air entering the pump as possible without air bubbles returning to the tank AND maintaining that air-water interface in the collection cup right where it starts to really get small.

Opening the air inlet valve will create more bubbles inside the reaction chamber. It will also decrease the height of the air water interface, and may cause bubbles to flow out of the diffuser (which should be in your tank as well). Closing the skimmer outlet valve will increase the height of the air-water interface, slow the flowrate of the pump, and possibly decrease bubbles from going back into the diffuser. Obviously doing the reverse to the valves that I just described will do the opposite things. So you need to tweak valves a little for the first week or so to get things running. On my skimmer (different brand, same features) I can open my air intake all the way. Some people cannot. I also restrict the outlet of the pump a LOT, again, some people cannot.

Is that the one you have in your tank ski?

 

[SkiFletch]

Nope, this is my skimmer. I've made some (many) modifications to it as well. Its a little too big to be a hang-on

 

[Ranger]

Mine is slightly different. The air inlet "valve" is there, but I have no control over air intake. My pump/powerhead thingy has a valve on it. It's a simply twisty valve (open/close) Everything else is the same. Its not a matter of bubbles coming out of it(well kindof), but moreso a matter of too much water. The water overflows over the top of the bubble diffuser(directions said to have it atleast half inch out of the water), and with the water comes all the tiny bubbles (micro-bubbles i assume). I've tried turning the dials every which way. The bubbles only seem to kick in when the pump valve is about.. 75-80% open, or else its just water, no bubbling or anything. I'm gonna go fool around with it some more...

EDIT: Ok, so i kinda messed with it. No luck, it that no matter what I do water still overflows out the top of the bubbler diffuser. The only thing I can do is close the pump valve. For example, now everything is fine except there is no bubbling. Just water running through the skimmer, what I did was close the pump valve enough(to restrict water flow), and close the outlet valve(again to restrict flow), but without sufficient power from the pump, bubbles seace(sp) to occur(?).

 

[SkiFletch]

Do you have the foam pad in the bubble diffuser? I was under the impression that the bubble diffuser was just a little internal box with a foam pad in it to catch the bubbles... Anyway you can take pics of it in operation? If not, I'll go play with the ones my LFS has on-site tommorrow when I visit and see if I can re-create your problem (and thus tell you how to fix it )

 

[Ranger]

yeah, give me a couple of minutes

 

[Ranger]

Ok, here we go, Ill explain they pics as they come.... And to your q.uestion ski, yes there are two types of foam thingies in there as they are supposed to be, as far as i know. Lol, i read through the directions a few times. Explanations will be below their corresponding pictures.

Here you can just see all of the (micro?) bubbles exiting the diffuser when they shouldn't be.

Heres a pic of water overflowing over the top of the diffuser, carrying bubblies with it.

Theres the top of the skimmer and collection cup. I'm getting what I think to be a "normal" amount of bubbling in the beginning of the funnel.

Here is a view of the top of the diffuser. The large bubbles are normal I think, but you can again see the water coming over the top of the diffuser, bubbles and all.


I hope these images work and help get the problem solved, even if it means that all I find out is that im a dummy and did something wrong.

 

[SkiFletch]

thats a lot of bubbles . Actually the picture I need to see most is the bottom of the skimmer reaction chamber I assume we're working with as close to natural seawater as you can get here yes? Cause doing this with freshwater or partially mixed saltwater is NOT gonna work, the water needs to have its full specific gravity to properly tweak

It LOOKS like your problem is too many bubbles into the reaction chamber, but you're telling me the skimmer didnt come with an air regulation valve? So you just have a wide-open airline hose feeding air into the venturi?

Since you have no livestock in the tank, I'd let it run overnight as-is. It is also VERY possible that there is something in your water that is causing exceptional bubble formation that needs to be skimmed out. Sometimes water chemistry parameters are just right to make a skimmer "go nuts" (yes thats a technical aquarist term ) and over-make bubbles. I've had that happen in my tank when I dosed carbonate into the sump chamber with my skimmer, thing went crazy for a couple hours and shot bubbles back into my sump. Your new water might just have something in it that makes your skimmer produce too many bubbles and just nees to run its course.

So for now, take a shot of the base of the reaction chamber if possible (although I'm pretty sure I know what it looks like and let me know if there are any air valves or air silencers on the airline hose. Then go to sleep and see what it looks like in the morning

 

[Ranger]

If by natural seawater you mean, did I go down to the beach and bucket it up... the no . But I mixed clean water with red sea salt, I'll test salinity now. Should I increase the bubbles flowing into the collection cup to speed up the skimming? I'll get that picture for you right now.

EDIT:

The image is flipped, should be vert.

Haha, im guessing this is what you expected. Can't see much, obviously. Tons of bubbles in there.

Also, I used some AquaSafe in some tap water instead of using RO. Possibly the cause? I didn't want to wait for my RO to pump out 20 gallons of water. In hindsight, with all this stuff ive learned, it was probably a bad idea.

EDIT 2: Here is a pic of my "air intake". The tube you see connects directly to the pump. And the open end is where the air enters... not sure what the cannister is for, I haven't found any way to regulate the airflow.