how to adjust my cpr bak pak skimmer

[SalteeDogg]

On the waste cup, theres a rubber band to adjust the height on it, I was wondering what the adjustment should be at. Like should the bottom of the cup be touching the top of the water in the skimmer? I think the adjustment is off on it because NO waste has been in it lately. If I made no sense let me know and I will try to re word it the best I can. Any help greatly appreciated. Thanks

 

[bobby]

The bubbles should be at the base of the cone on the cup. I owned one but could never get in real good. I thought I liked it at first, but ended up selling it and buying a new skimmer.

 

[SalteeDogg]

went to adjust and there were no bubbles by the waste cup. Right now I just have it were the bottom of the waste cup touches the water, I dont know if thats right or not or if it should be pushed down a little more?

 

[bobby]

Sounds like your venturi is not sucking in air. You should always have bubbles. Check your line for a blockage, the valve it see if it's closed, or the part of the pump were the air line attaches to for a blockage.

 

[SalteeDogg]

ok im lost so try to help me out. Theres a clear line that comes from the pump and its attached to the top of the skimmer. It has a black knob on the end of it to unscrew or screw in. Its screwed all the way in. Do I need to unscrew this a little?

 

[SalteeDogg]

Also should this tube be in the water or up out of the water? It use to hang in the water but I put it back in its black clip thats ontop of the skimmer?

 

[SalteeDogg]

Just opened the valve and its blowing bubbles now. So the bottom of the waste cup should be touching the bubbles or the bottom of the square part on the waste cup? Im confused?

 

[Rcpilot]

That black line is your air intake. I think you figured that out already. You'll have to play with it and screw it in or out to get maximum bubbles. It will get full of salt creep and reduce the amount of bubbles in the chamber. You have to take the screw out and use a turkey baster to inject clean RO water down the tube every 2 or 3 days to rinse the salt creep out. Then put the screw back in and adjust the bubbles for max bubbles. All it takes is a tiny tweak 1/32 turn either way to have lots of bubbles, or hardly any bubbles. Pay attention when adjusting it. Takes some patience.

On my CPR refugium (same cup and black o-ring) I have the bottom of the cup about 1/2" under the water. Well, not the CUP, but the flat flange at the bottom of the cup where the funnel is. The bubbles are formed up inside the cone/funnel at the bottom of the cup. Might be wet skimming, but it's brown and smells completely awful.

The directions on my refugium say to have the bottom flange of the cup under water about 1/4". I have it set under about 1/2" because if I only set it down 1/4", it takes forever to get any foam.

 

[bobby]

Yes that is right. You might need to adjust the bubbles as well with the screw in part. It will take time to get it dialed in just every few hour make tiny adjustments till you get it were you want it. I'm pretty sure the bubbles need to be at the base of the cone part of the cup. Just take your time and dont do anything too fast.

 

[SalteeDogg]

Thanks guys!!! I had to open up the screw all the way because if I dont it would blow a billion micro bubbles in the tank. So I opened it up and no bubbles in the tank and it looks like I see foam going up to the waste cup.

 

[Rcpilot]

Don't open it all the way. That won't give you maximum bubbles in the chamber. You want to open it just enough to fill the entire chamber with bubbles. The bubbles should be so thick that you can't see through it.

Look at the pics I posted above.

You are probably using the black tube that came with the powerhead. I would suggest replacing it with a piece of standard clear airline tubing. That way you can see through it. The air intake tube will get clogged with salt creep every couple days. It really screws up the bubbles because the tube is restricted. These things are VERY touchy. You need to have the little screw adjusted just perfect to get maximum bubbles and maximum skimming out of the unit. Keeping the air intake tube clear of salt creep really is mandatory. With the black tube, you can't see through it and you won't know when it's getting clogged with salt creep.

To clean it:
Just take the air intake screw all the way out and fill your turkey baster with some fresh RO water. Insert the turkey baster into the air intake tube and let the water flow through it. That will wash the salt creep out of the tube.

Now you will need to adjust it again. On my unit the screw works best about 1/2 turn from all the way closed. They are extremely sensitive. 1/32 turn too far open, and you will get a blast of bubbles from the black powerhead tube, but not enough to really fill the entire chamber with bubbles. Too far in, and you are loosing efficiency because there aren't enough bubbles to really produce any skimmmate. Take the time to adjust it. It really works great, but don't rush it and make TINY TINY TINY adjustments. You should be able to get that entire chamber completely full of bubbles. That will give you the best skimming efficiency.

The way you have it now is working for you because you don't want the microbubbles in the main display tank. TRUST ME--the unit takes a few days, or even a week to break in completely. Once it breaks in the bubbles in the tank will disappear. The unit will get more efficient as a coating of slime builds up on it and you will see minimal bubbles passing into the tank.





They still take maintenance almost every 2 or 3 days if you REALLY want it to work good. It's not something you can just adjust once and let it run for a month without messing with it.

 

[WannaRace]

I've got the same skimmer and RC is right 100%

The only other thing I have to offer you is if you are not satisfied with the amount of foam you are collecting in the cup, then bring the cup as low as possible so as to collect as much bubbles, whether clean or dirty water, and adjust the height from there.

 

[SalteeDogg]

Well I think I finally got it adjusted right. Was working great last night but when I checked it today it needed adjustment again. I think I got it worked out pretty close to what it should be. Good vid's by the way. Thanks again

 

[SalteeDogg]

One last question, should the foam of bubbles be going in the waste cup at all times or just every so often? When I adjust it I can usually get it to foam up to the waste cup but after an hour or so no foam will be coming up but all the bubbles in everything look normal?

 

[Rcpilot]

The way any skimmer works if off surface tension of the water. Each little air bubble is surrounded by water. So, there is surface tension around each bubble.

The dissolved organic waste (DOW) -- i.e. fish poop and uneaten food-- is basically an oil slick now. Once the food and poop breaks down into goo, it is like an oil or chum slick on the surface of the water. That oil gets sucked into the powerhead and pushed through the column of air bubbles. The DOW stick to the bubbles because of the surface tension between the air and water outside the bubble. The air bubbles rise and pop on the surface--under the collection cup.

That creates a sludge or thick mass of oily goo right under the collection cup. Other bubbles come up under it and force it into the funnel where it finally gets shoved into the cup.

If it ain't skimming, it's either
A: not broke in yet. Give it time.
B: the tank is clean and there are not enough DOW to form any skimmate
C: the collection cup is too high

 

[WannaRace]

RC, out of curiousity, how long does it take for your collection cup to reach halfway?

 

[SalteeDogg]

Thats a good question, I would like to know too!?

 

[Rcpilot]

RC, out of curiousity, how long does it take for your collection cup to reach halfway?

I think that depends on how efficiently you have the skimmer tuned, and how much crap is in the water. Also, if you have the cup set down low--it will skim fast and it will be kinda watery. Color is yellowish/green/brownish. I can raise my cup way up and get really NASTY dark brown skimmate, but it takes a long time to get any in the cup. A lot depends on how far down you set the cup.

I keep mine tuned up pretty good and I feed a LOT. I feed my fish everyday and I feed Marine Snow and 2 Little Fishies trace elements twice a week in small doses. If I run the skimmer 24hrs a day, it takes about 2 or 3 days to fill the cup 1/2 way.

Lately, I've been skimming only at night, when all my polyps and zoas are closed up and not feeding. I turn it off during the day so they can absorb nutrients out of the water. I think they are growing better now.

Either way, I think you'd have to work really hard to fill the cup in a weekend. Don't be afraid to leave town for a couple days. If you're worried it might overflow--just turn the air intake off and let the tank run skimmerless for the weekend. I left town for 5 days and left my skimmer turned off. Came back to some algae on the glass, but my corals sure looked happy.

The debate with skimmers is that they take the organics out of the water--and thats EXACTLY what our corals want to eat. So, the tank looks clean. No algae. But the water is stripped of nutrients that our corals need in order to grow and thrive. Catch 22.

 

[SalteeDogg]

thanks for the more info!!! I'll try to cut back on the questions I know im probably giving you a headache by now!

 

[WannaRace]

I was just looking for a single number, that's all! :) JK

I appreciate the response. I was just curious how my tuning is up against yours and mine will usually take a good 3-4 days to fill the cup halfway with nasty water, just a tad lower than yours in the video. Looks like all is well!