Coralife Luft Pump... quitting against a skimmer...     3/4/13
Hi,
<Ross>
I have a question about the Corallife Luft Pump,
<I too am a huge fan of this product... have toured where it used to be made in Germany (by Tetra) and in Blacksburg, VA where the company moved its manufacture...>
 but didn't see this query in your FAQ's.  Here's my set-up:  In my classroom, I have a 100 gallon, cold, salt water tank.  The Luft Pump is attached to an ozonizer which is attached to my protein skimmer.  I've been a fan of the Luft Pump for years because they last so much longer than any other air pump I've used....until now.  Recently, my old Luft Pump had lost its zip so I ordered a repair kit and a new pump, just to be safe.  I replaced the diaphragm and it worked well, briefly.  I thought, "Wow, that's a bummer.
I can't believe it wore out so quickly, but it happens."  So I replaced it with the new pump.  The exact same thing happened.  It worked great for a day, and then it barely seemed to push air. 
<Mmm... I suspect some sort of back-pressure issue here... the skimmer... is this a wooden airstone type? I'd ask that you try blowing through the 3/16" ID airline tubing... can you produce bubbles? These "stones" need to be replaced every few months... sometimes more often>
Since I was out of pumps, I decided to run both a the same time and use a splitter thinking that maybe two weak pumps would be equivalent to one good one. 
<Uhh, no... either can/will produce near 9 psi... will produced more air volume together w/o resistance... but the discharge has to not be higher resistance than the 9 psi>
Here's the weird thing:  I found out, by accident,  that if I unplugged the pumps, just for a minute, they would work perfectly for hours after.  So clearly, nothing is wrong with the diaphragm.  Are they over heating?
<Again, the airstone/s... overheating, yes>
 If so, it seems unlikely that a minute would cause it to cool off significantly.  If over heating is the case, what could I do to prevent it?  Could it be something else?
<Ah yes>
 My routine now, when I come into class, is to unplug the pumps, let them sit for a minute and then plug them back in.  Clearly, I can't do this indefinitely.  Any suggestions?
<Look into replacing the limewood airstones w/ fused glass bead types... A few folks make these, but you may have to order... If all else fails, http://www.aquaticeco.com/
is a good source.>
Thanks,
Ross Henderson

Lighting, Skimmers and a dearth of info provided -- 11/14/11
Hello,
<<Hi there>>
I accidentally bought a 20k light bulb and I think I can just use it as a weaker actinic light bulb.
<<Or maybe return it for credit/exchange>>
Can I use this bulb with a 10k bulb?
<<Sure'¦though whether this combo gives the needed light intensity I have no idea as you have left out any detail of your system. Do have a read here and among the associated links at the top of the page (http://www.wetwebmedia.com/marlgtganthony.htm)>>
Also, how would I use a powerhead for a protein skimmer?
<<Not enough information to formulate a response>>
If I can't then do I have to use only limewood air stones
<<Ah'¦if your query re the powerhead is to provide the 'bubbles' for a skimmer, this likely will prove insufficient. Best to stick with the original design, or purchase a different/better skimmer>>
or can I use different ones?
<<In my experience with air-driven skimmers, most anything other than Limewood air diffusers have proven disappointing as they just don't produce a fine-enough bubble, in my opinion. You can 'make' a fairly suitable substitute from Basswood (can be found at arts-and-craft stores like 'Michaels'), if you have the tools/are a bit handy. Otherwise, I