Gen-X Mak4 pumps

Discussion in 'General Reef Aquarium Discussion' started by BoomerD, Jan 9, 2004.

  1. BoomerD

    BoomerD New Member

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    Anyone have any experience or tales to tell about these? I like the advertised flow rates & electrical consumption. Are they noisy? Dependable? Bad heat transfer? Any reported problems with them? just plain junk, or very good? I'm considering using one for the closed loop on the new 180 and would like to know it they're worth the $$$.
    Thanks,
     
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  2. Pro_builder

    Pro_builder New Member

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    I have done a lot of research on this pump.
    I haven't heard any bad things about them at all. They use a lot less power and make less noise then the Mag Pumps, is all I have heard. Although nobody has had them very long (That I spoke to) so no info on lifetime, or reliability issues.
    HTH
     
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  3. PSU4ME

    PSU4ME JoePa lives on!!!
    RS STAFF

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    Does anyone have anything else to say about the mak4 pump? I was thinking about getting.

    Thanks
     
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  4. PSU4ME

    PSU4ME JoePa lives on!!!
    RS STAFF

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    Can these pumps handle back pressure?
     
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  5. BoomerD

    BoomerD New Member

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    They are supposed to be pressure rated pumps. I bought one just before the knee surgery, but still don't have it running yet. Back has been too screwed up to allow me to get under the tank and do the necessary plumbing changes.
     
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  6. joe@inreef

    joe@inreef Sponsor

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    Extremely reliable.... have sold about 60 of the Gen-x pumps, and have yet to get one back. The Mak-4 is now the PCX 40. You can check the specs on our site. We also carry the PCX-100, similar to the Iwaki 70, and the PCX-30, which is similar to the Iwaki 40.
     
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  7. Hooked

    Hooked New Member

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    Well, I guess I'm going to have the dissenting opinion here. I've been running one on a closed loop since September. I thought it was great at first, maybe just a little noisier than I'd like. But I've had a microbubble problem pretty much from the start. At first I thought I had a leak in my closed loop, but I rebuilt the closed loop to remove the SCWD. I still have a problem and it's getting worse. I can fix it by shutting the output side ball valve to about half flow. I looked for threads about cavitation, but didn't find any on this board and only a few on some others; however, I feel pretty certain that is my problem.

    As far as other pumps, I just installed my chiller this weekend and I used a a PanWorld/Blueline and it is so quiet. I belive these are Iwaki "knockoffs." I'll eventaully be replacing the Gen-x with one of these when I get some extra cash. :cool:

    HTH

    By the way, if anyone has a solution to my microbubble problem, I'd love to hear it!!!
     
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  8. tommyp

    tommyp New Member

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    Mine is a year old or so and going strong. It is louder than I would like because it is in my living room but it is an excellent pump. Great value for the dollar. No bubbles here.

    Tom
     
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  9. Cosmic

    Cosmic New Member

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    When you begin to start seeing microbubbles from your pump, you either need to cut back the flow (As you did), or upgrade all your plumbing to the next bigger diameter PVC. This will cause less friction and less micro-bubbles.

    I'm looking into these pumps now as well to run my new honking skimmer. I've looked into the Iwaki RLT40's, but the price is a bit more than I want to spend right now. This pump seems an excellent alternate, but user reviews are the final tell-tale for me.

    Any other opinions on the GenX pumps?

    Cos
     
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  10. Hooked

    Hooked New Member

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    Cos,

    I was wondering if larger diameter PVC was a cure. Would I have to upgrade on both side of the pump?

    As an additional note, I was at Premium Aquatics Friday afternoon and mentioned the problem with the pump. I also mentioned it was noisy. They have one running on one of the tanks in the office and it is silent, so I think I may have a defective pump. I'm going to swap it out in a couple of weeks for a new one.

    I have my output throttled back about half (not what you want to do in an sps tank) and now the bubbles are mostly gone. I say mostly because occasionally it will blow some out again for a short period of time, whereas before it was constant.

    I'll let you know what happens when I get a new pump.

    Thanks
     
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  11. Hooked

    Hooked New Member

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    #11
  12. dwall174

    dwall174 New Member

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    Pump Cavitation

    Have you seen This One
    It sounds like you might be restricting the intake some how? Do you have a 90 degree fitting or a plumbing reducer within 6" of the inlet? This could be causing a restriction on the suction side of the pump! This could also be what’s causing a lot of noise from your pump.
     
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  13. Hooked

    Hooked New Member

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    Thanks for the link dwall. I do have a 90 close to the intake side of the pump. I'll have to look tonight to see how close. Perhaps that is the problem. My noise is not the same as described in the article you attached. I've read other articles that described the noise caused by cavitation as sounding like gravel going through the pump. Mine is just a very loud hum that I can hear distinctly over all the other pumps and water noises.
     
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  14. tommyp

    tommyp New Member

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    Mine hums no 90 it is direct bulkhead to the sump. I have 3/4 to 1" bushings on both input and out.

    Tom
     
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  15. Cosmic

    Cosmic New Member

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    Hey Katrina,
    Thanks for that link above on the Panworld pumps. I found the same pump under the Blueline HD series name as well, and bit the bullet and got THIS ONE.
    Same company, but manufactured for US distribution possibly?

    Comparable to the Iwaki 55RLT, which is more than suitable to run my beckett skimmer :)

    Have you gotten your problem fixed yet?
     
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  16. Hooked

    Hooked New Member

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    So Cos how do you like the new pump? The little one I have on my chiller CL is virtually silent. I'm hoping the larger ones will also have that quality.

    I haven't gotten my probelm fixed yet. There is a 90 degree bend in the intake line within six inches of the pump. I plan on working on that the weekend after Easter. Do you agree that is a likely cause? I'm asking because it is going to be difficult to find a place to put the pump without that 90 in there and I hate to go to all the trouble only to find I still have the problem. Also is it likely my pump impeller is damaged and the pump will need to be replaced?

    Thanks :cool:
     
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  17. Cosmic

    Cosmic New Member

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    I haven't gotten the new pump yet. It should be here by middle of next week I'm hoping. I'll be sure to post back on my opinion of it when I DO get it running though :)

    If it's just a loud hum you hear, I doubt you will need to replace the impellar. Most likely scenario is the elbow is just restricting the intake of the pump, sort of like cutting it back by using a ball valve. Once open, the pump won't be restricted and should run normally for you. If the impellar IS bad, you would most likely be hearing "crunching" noises coming from the pump.

    Is there a reason you need the elbow on the pump intake? What about moving the pump further from the source, so that a longer (read over 6") extension is needed before the elbow? This may be a bit easier, but I can't say without knowing more about how everything is set up.

    Just a thought,
    Cos
     
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  18. Caterham

    Caterham New Member

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    Katrina,

    I always like to start this explanation by relating it to the rear end in a car. In a car, the rear end (or drive end in case of front wheel drive) has what is called a differential. The purpose of the differential is quite simple, and can be applied in any pump application.

    When we take a corner in a car, the wheels are required to spin at different speeds. If you take a 90 degree right turn into your driveway, the right side wheels have far less distance to travel than the left hand side. In this situation the left hand, or the "outside" wheel is turning several more revolutions than the inside wheel to make the same turn. Both sides of the car end up pointing the same direction when the turn is over but the outside wheels travelled further. Pretty simple concept. Lets proceed :cool:

    On the suction side of any centrifugal process pump, the same rules apply as far as making the turn. In your case, the saltwater on the outside must travel further than the saltwater on the inside of the 90 degree turn. Also, just as the outside wheel on the car starts to go faster (more revolutions), the saltwater on the outside of the 90 degree fitting is travelling farther to reach the same destination. The problem now is that the velocity of the saltwater on the outside of the fitting has increased as it is trying to catch up. As the velocity of any fluid under pressure increases, the pressure drops. Now there is a velocity differential, thus a pressure differential right in front of the impeller. Not good.

    Books with over 500 pages have been written on this topic and I am not going to bore you with a bunch of scientific crap. Get rid of the 90 degree fitting. If you must use it to make your set up work, then allow 10X the diameter of the pipe BEFORE the fluid hits the impeller. There must be a straight shot of pipe going into the pump. This will give the fluid a chance to equalize pressure and the impeller will treat it all the same. If you have 1" pipe, allow 10 inches of straight PVC before the pump and so on.

    Also, never throttle back the discharge of a pump. NEVER. This creates a hydraulic force within the pump that tries to bend the shaft. Its not my opinion, its just the laws of physics. If the pump is oversized and creates too much flow, just install a discharge bypass. This can be done with a simple T fitting and a ball valve. Install the T fitting on the discharge of the return pump just at the top of the sump, immediately followed by the ball valve. Run a line off the T fitting back to the sump. If your pump is oversized and creates too much flow, throttle back your bypass valve and divert the water back to the sump. This will give you the perfect amount of flow to your display and let your pump operate close to its best efficiency point (BEP). When a pump is running off of its BEP it runs hot, wastes energy and always ends in premature failure.

    Get your plumbing straightened out first, then determine if the pump has been damaged. You might find that the pump operates to your liking when properly piped. It could have sustained some damage depending on how long it has been running in its current environment. The GEN-X is a good pump.

    If you have any questions about setting up your pump, please do not hesitate to ask. I want to help!
     
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  19. Hooked

    Hooked New Member

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    That is a great explanation, thanks.

    My pump is not oversized, I want to run it wide open, but the bubbles were driving me nuts. I'll reconfigure the plumbing based on the guidelines you provided and report back!

    Thanks for helping :)
     
    #19
  20. UnderWaterParadise

    UnderWaterParadise my name is Rob and I'm a Zooaholic

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    Any updates on this? I am trying to read as many plumbing and pump threads as possible
     
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