I'll save you the trouble. No. A MAK 4 isn't going to run that skimmer. My skimmer was smaller than yours and the MAK 4 was just enough. The Iwaki 7 I tried was much better, and the minimum you'd get away with.
For a new approach to this, maybe try cutting the tube down to less than 18". Then the MAg 18 will work, and you'll still hae more skimme than you need.

mak5
 

dude
if u'r going to stay with that size of skimmer, don't waste your money with mak4. go straight to mak5/iwaki70 (or even iwaki100.) they all take up lots of $$ to buy and lots of $$ in electricity
looking at your pics, i don't consider that "tons" of bubbles. in my skimmer, the bubbles are so thick its like milk and you cannot see through to the other side. In fact it doesn't even look like water in the chamber. take a look at the chamber of my skimmer:
http://www.canreef.com/photopost/dat...9_3919-med.JPG

Mine's using an iwaki70 now with the same results. my skimmer stands 48" tall total including the box so chamber is about 20 inches high and the top tube and collection cup is about 20 inches as well.
hth

Well i dont have 400 dollers to spend on a mak 5 of equivalent, i know canadian man has a skimmer similiar in size to mine and is using a mak 4 with good results. When i say lots of bubbles i mean in the down pipe.

If youve removed the 90`s that are in the base of the skimmer, try it first before you cut anything down.

The bubbles are going to take the easiest way....and right now that is going straight back up the injection tower...that is why it spits too.

The size of the reaction tube right now has nothing to do with the problem... if you cut that tube down, it will be a smaller tube, still with no bubbles in it.

It doesnt matter what the height of the reaction tube is...you can place the water at any height with a valve on the output of the skimmer.

dont worry about bubbles in the sump right now, baffles and buckets and bags can be used for that, atleast the majority can just rise up the reaction tube instead of getting stuck in the injection tower.

Marc.

Canadian Man's skimmer reaction chamber is no more than 26" tall.

How do I know this? I bought the acrylic tube that it's made of! I have the other 26" and it was a 52" off cut. :razz:

Like I said, I know it's kinda sucky to hear this, but, what I would do is go to the Mak4, AND cut the skimmer in half. I know it's not quite what you want to hear, but another thing to consider: you have to get into the skimmer once per week to clean it. How can you even reach down into it if it's 48" tall?

Look on the bright side, you could probably sell the offcuts.

Im not sure what ive said in the past but as of this moment the actull reaction chamber is just above 30" tall on mine. Im going to test the mag 18 tommorow. But if that doesnt work im going to get a mak 4.

I personally don't think you really need that huge of a pump to drive a beckett. It all depends on the design... Let me explain.

http://www.canreef.com/photopost/dat...mmer_small.jpg

The reaction chamber in my skimmer is about 38" of 6" diameter tube.
The total height of my skimmer is 52" tall. I am only running a T3 (Custom Sea Life) pump which is pressure rated 800gph at 0'. However, by beckett shoots straight down into the reaction chamber with no elbows. I think this makes a huge difference. I don't know if you really have to go with a bigger pump.

Des

PS that skimmate is only 8 hours worth in the cup

Dez, he either has to make a modification, or he has to upgrade his pump if he doesn't want to touch the skimmer itself. I'm sure a swimming pool pump would run that skimmer just fine as-is. If it was me, I'd be looking at both pump and design: a mag18 draws 145W and a Mak4 draws 110W, so the Mak4 is cheaper to run, AND I think will perform a little better on a larger beckett skimmer (although it is not going to solve the problem with the skimmer as it is now). So I stand by my comments, although, for sure, it's not the complete solution.

Sean, I think one possible key thing to focus on here is the length of the injector assembly. If you really want to avoid shortening the reaction chamber any further then look at least at shortening that (should your next run of it, without the 90 degree bends in the bottom, turns out to not fix it). I know that your original idea was to increase contact time but it seems to me that you're now faced with a "too long" contact time? Dez's skimmer shoots water right into the reaction chamber, but also significant, I think, is that this means his injection tube ends up being shorter.

Just a question though, how long is the feed pipe from the pump to the injector? What diameter pipe is it (it looks like 1")? Is there anything that could be restricting the pump at all. How old is it? If it's second-hand .. what shape is the impeller in? You'd be surprised at how little of a restriction on the pump (or a particle of crud in the becket itself) can adversely impact foam production.

The pump is practicly new, used for maybe a week or so. Its on inch pipe then 3/4".

Ahhh .. well for one get rid of the 3/4", redo it in at least 1". Also try to avoid excessive 90 bends, if at all possible. Probably the best option is to go with 1" flex PVC, if not, then use 2 45's instead of a single 90 (and so on).

You wouldn't believe the difference switching from 3/4" to 1" made for me. Also I was using a short length of that ribbed 1" pond lining. I don't have any stats to back me up but I'm convinced that the ribbing puts too much friction into the equation, I would think that the flow through 1" ribbed pond tubing is equivalent to 3/4" tubing without.

I don't have the equations handy but flow through a cylinder increases exponentially with increases in diameter. E.g., comparing a 1" cylinder to a 2" cylinder, the total flow is 4x as much in the 2" as the 1", despite the diameter only being 2x as much. I guess my point is, don't discount the pipe diameter, it's significant.