I ordered a tetra 150 off ebay and received a 300. Opened it to see if it was the same to convert, but it's a little diffferent. Found a way to convert it to a vacuum without doing much, but I'm wondering if anyone else has done it, and if so, how.
On one of the Q&As they mentioned that the repair kits for the 150 are what you use on the 300s, you just need two of them.
Done and done. All I did was turn those 2 doodad thingys around and it now sucks instead of blows. I remember shaving some plastic tab down to make it fit perfect.
The insides of the pump I have are different from the images I’ve seen of the 150. The parts that they normally reverse are screwed together and the whole thing does not slide out like the images of the 150.
Just check my getup and I have the 150. Disregard all my insight into the inner most limits of pure 300
The inner works of the 150 are screwed into the chassis and the diaphrams themselves are screwed in into the pump. The rubber bellows are screwed onto the arms (which are hinged) but they pop off the pump assembly just like the covers of a spark plug wire in your car. So you don’t need to take the bellows off of the arms - just pop them off the assembly and swing them out of the way.
I can’t imagine why the bellows would be screwed onto the diphragms.
If the parts are wrong on the 300, file an eBay dispute and get your money back if you can sharkcountry, since they did not send you a Whisper AP 150.
I picked up a couple of new AP 150s at Amazon.com for $26 each, with free shipping.
EDIT:
Houston we have a problem. I just checked the inner works of my new AP 150s. They too have a pumping plate mechanism that is different from the older models. It is a central plate with two clear plastic pieces, one attached on either side, screwed together and placed between the 2 diaphragms in the center of the pump. The diaphragms are not mounted on the outer housing walls like previous models. It seems they have been re-designed. It looks like disassembly of the central plates could be aggravating, assuming the clear pieces can be reversed for suction. I (we) may be screwed …
I guess we’ll have to take a look inside some of these other pumps to see what’s easy.
These types of pumps are soooo quiet.
Roger there’s an air inlet on the top of the small box that is between the 2 diaphrams. Just connect a small hose to that and you get vacuum there. One problem is that once you get to clamping pressure the magnets will start hitting each other and make a loud noise. I put a small piece of plastic in between the magnets and that takes care of the noise. I’ll need to find a way to securely fasten a plastic or thin rubber piece and I’ll have a vacuum pump that can still be used in an aquarium.
I also need to decide how I want to have the new hose come out of the case. I thought about replacing the hoses that are currently used for the exhaust, and I think that may be the best option. Just pull off the hoses there now and add a hose going from the top of the part that creates the vacuum/pump and attach that the where the exhaust hose was. Then close the pump. It will be much quieter if it’s closed up.
Overall I can’t complain the 300 is more expensive and it has twice as much pump, so I think I got a good deal.
…
The new pumps do not look as easy to rebuild as the old models were. I do not want to damage the pumping mechanism by disassembling it the wrong way. I called the Tetra customer service number and asked about the correct way to replace the diaphragms on the new system. He asked how many pumps I bought and then said he would send me a rebuild kit gratis because the replacement instructions are only included in the rebuild kits. I will wait until I get the rebuild kit/instructions before I make any significant modifications.
The new models are still very quiet. Hopefully I can come up with a simple fix to convert the new AP 150 for vacuum.
Shark,
Seeing Gdaddy’s post of his aquarium pump vacuum unit again in another thread, I decided to pull one of my newer re-designed AP-150s appart and see what could be done simply to modify it for suction.
If you are patient for disassembly, modification and re-assembly; the AP-150 can be modified for suction with minimal changes. I just did it. The air output jet now sucks air. I am assuming your AP-300 has the similar clear plate setup between the diaphragms.
The clear plates can be rotated 180 degrees and re-attached. But you have to file a small groove in each of the clear plates so they will align with one another when flipped 180. The magnets do clatter a bit when max. suction is reached.
Hey Gdaddy, I can feel the suction of the intake. Thought it would suck harder. Although, I have no idea how much is enough by touch. How hard does the suction on your old-style 150 unit feel against your finger tip? How big a coin can you lift with it without out it falling off?
I took some pics of the original vs. the modified plates: original attached, loose and re-attached. I’ll start a thread once I get the photos culled and re-sized for posting.
Yeah, I had to file the nipple off before flipping them as well. It’s there to prevent users from accidentally installing the diaphragms backwards, which is exactly what we’re doing.
My pump is also the AP150. It’s a dual-bellows pump. As I understand it, the AP300 has two of those assemblies in it and 2 ports instead of just the one.
The suction directly off the 1/4" hose feels really weak on your hand. You don’t realize what the vacuum is doing until you connect it to a wider intake like the “vacuum port” I’m using. That’s when the 10+# draw becomes apparent. I know what the draw is because I ran it once with the reservoir and vacuum guage I use with the other vacuum pump I have here (it’s an industrial pump). This thing runs so quiet I literally cannot hear it unless I’m within 5-10 feet or so in a quiet room.
I’ve clamped fin panels together with that pump, glued a bunch of wood veneers with it and a couple other little vac-jobs just to see what it will and won’t do. I still have the bigger industrial pump with the reservior so i can pull 29# if I really needed to, but that doesn’t seem to be the case with surfboard stuff.
The pump doesn’t move a lot of volume, so I use a household vacuum cleaner to draw most of the excess air out of the bag before sealing it all the way up and letting the fish pump do it’s thing. Turn it on and leave it on until you’re done with it. For surfboards the primary limitation seems to be the integrity of the vacuum bag - it doesn’t move enough volume to keep up with a leaky bag.
Just a thought, if you can’t rework the innards to make it suck air instead of blow it, you could make some sort of venturi type pump if the output is high enough. Although I feel like you need a really high flow rate out of the pump to have any significant effect to do this.
@ Gdaddy, the newer 150s and 300s do not have the bellows/diaphragms attached to the outer wall of the housing, i.e. not like the picture above. The plates I am flipping are clear plastic. The diaphragms are attached to these plates in the middle of the housing and are pulled towards the middle by the magnets. The modification is a bit different but for the same reason – the small grooves in the plates are to keep you from putting them in backwards (180 flip) and causing suction (do not want to drain the aquarium through your air pump). When I post some pictures, you will see what I am talking about.
The modification is fairly simple. But re-assembly is tedious and at times a b!tch, several tiny screws with hole alignment needed between the two clear plates. For this modification, pictures are worth a thousand words. Bottom line the new 150s and 300s can be converted. I need to work on the magnet clatter, maybe some O-ring collars to keep the diaphragms farther appart.
@ Drzoidberg, air-flow rate is very low with these pumps. Not nearly enough air flow from these pumps to generate any venturi suction. As Gdaddy says, this is a hack setup (shed tech) using what you have in the closet. Got two new 150s on-line for approx. $25 each a year ago.
It’s been a while since I reworked mine, but if I remember right just unscrew the four screws on the clear plastic part then roate those clear parts 180 degrees (so they are upside down to the factory position). The alignment notch will also now be opposite and won’t line up, so you just have to have chisel it off. Reassemble and you are good to go.
How much of a vacuum do these little pumps pull and what are they useful for?
These Whisper aquarium air pumps are designed to run continuously 24/7/365 for several years with little or no maintenance. But air flow is slow. Gdaddy says he pulls 10-11 inches. I will assume he means inches of mercury. I have used Whisper air pumps over several decades for aquarium and slightly larger aquatic tank biofilters and airlift water circulation
The following is what Gdaddy posted a while back that caught my interest:
http://www.swaylocks.com/comment/456084#comment-456084
Gdaddy’s setup:
