Wait, back up a minute...
Well, sure, but if you are running that much wattage in light (over 2500watts is enough for a 1000g if you set it up right), you must have a 600g + tank in the first place.... in which case why would you just be using a KZ small or BM250 in the first place? Both of those skimmers are WAAAAAAY undersized for the size tank you must be running. Your skimmer should be in the 85-150 watt range as a needlewheel, and 300-500 as a venturi/beckett/etc. Not a small Aquabee 2000/1 pulling what... 28 watts maybe?
Lets be realistic here. The KZ small you have is run by a Aquabee 2000/1 and in this configuration must pull only about 400lph of air. Yet its rated for up to 396 gallons by KZ: Yeah, right, on a good day. I wouldnt run that on more than a 125g the way I stock a tank, there is just not enough air interface created with only that much air intake to skim a larger tank. At a bare minimum, with the most effective skimming methods on a tall skimmer, you still want about 4l/h of air per gallon of display. Sure, the KZ may look like its pulling tons from your water, but thats what happens when you run an undersized skimmer on a large tank... there is just alot more nutrients in the water, so the smaller skimmer has an easier time where a larger skimmer has to work harder because its skimming more than the tank can produce after the first few weeks of service. So the smaller skimmer looks like its performing better... but unless you have taken organic tests to compare before and after, its all relative.
A BK250 pulls 2000lph of air (and this will increase to even more with the loopwheel) and is rated for tanks up to 525 gallons... which is more realistic IMO. Id go more like 250 gallons with it, maybe 300... but still... its a much larger skimmer in every way. Perhaps too large for your system? I dont know what your tank looks like, or specs or anything, so I cant comment.
You gotta look at how the skimmer is sized with the system. With short/bubbleplate style skimmers like the BM and BK (and ATB, etc) the bubble efficiency isnt as great as with a taller skimmer, sure, so you need to match the skimmer size better with the actual bioload of the system. You often see bubbleplate skimmers performing better on tanks with a high load, as if there isnt enough to skim in the water, the bubbles pop in the neck more and less skimmate gets into the cup. Something tells me that the BK250 on your system was too large, and it hit the point where it couldnt skim anymore. So you went and put a smaller skimmer on, and sure enough... you have more skimmate because the skimmer rating isnt about the tank as it is about the inhabitants. So you just cut your skimmer size by 3/4 and sure enough... its looks like its doing so much better even though thats just because it cant keep up. You see it having an easier time making skimmate, but that is not a true rating. Try testing the organics of your water. If you have more than a dozen fish in your 600+ gallon tank, and a couple dozen corals, you will end up with a higher amount of organics that the smaller skimmer cant remove. The skimmer will look like its doing more, because its undersized, but come on.
Also, look at the ratings here. You are comparing the KZ S for $900 to an $1800 BK250. The tank ratings dont even match up. The correct KZ to compare here would be the KZ M, which is a $1750 skimmer!!! Same price. Taller and skinnier, and with an Aquabee 6000, you are talking about 800lph of air maybe (as a needlewheel it could be double that). Its rated for up to 924 gallons, but I think we can tell that KZ's ratings are very liberal at this point. Id say for a 400-500g tops.
I bet if you put the KZ M on your system, as low a bio-load as it must be, you would have similar problems as you had with your BK250. You must not have alot of fish or corals in that huge tank of yours.
And as far as wattage goes, no, running such an undersized skimmer on a tank with over 2000 watts of light prolly isnt a huge deal if its needlewheel or beckett, or whatever. But if you have a decent bioload of fish and corals, your tank will need something larger... and then we are talking much higher wattage like I mentioned above. And then its not about the cost in electricity, but the heat.
This is where a needlewheel pulls away. A needlewheel can get more air intake with a smaller pump. So that 100 watt Aquabee 5000 thats acting like a 50watt heater (yes, same as a 50 watt heater!) is more of a thorn in the side than a BK running at 45 watts total.
And KZ wants to have an actual utility patent on their skimmers? Come on. I bet that patent gets denied because its already patented by someone else. Whats to patent? Beckett has a patent on the nozzle. The cone shaped body? Wait... ATB, ATI... they all have it too. The plankton-friendly claims are bogus as well (captive reefs dont produce plankton in the water column like the open ocean).
