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Pump specs?

Discussion in 'Lighting and Equipment' started by dweeb, Aug 8, 2017.

  1. dweeb

    dweeb Copepod M.A.S.C Club Member

    Moved into a new house and finally got my salt mixing station (with RODI system) set up downstairs. That means no more wheeling a huge trashcan into the living room for water changes.

    But there's a problem: I am only running 1/4 line. I have an ATO line, as well as the line to pump mixed, fresh saltwater into the tank.

    The pump has to push saltwater through that 1/4" line, around 50-60 feet. It has to lift the water about 8-9 feet.

    Had a friend give me a pump that pushes 550gpm, with head pressure of 12 feet. But it hammers the line...it works, but it feels like it's trying to push too much water too fast through a little line.

    Anyone here a hydraulics engineer? :) I know nothing about this.

    Ask me how to pass a bill through the legislature and I can detail it for you, off the top of my head. But this has me baffled.
     
  2. Balz3352

    Balz3352 Marlin M.A.S.C Club Member

    Sounds like a need a peristaltic pump such as a masterflex
     
  3. zombie

    zombie Barracuda M.A.S.C Club Member

    I'm not a hydraulics engineer, but I know enough about fluid dynamics to be dangerous.

    The 1/4" line may work okay for ATO, but not for filling saltwater (unless you want to spend 3 hours filling 10 gallons) but if at all possible I would use 3/8" for that and upgrade to the Neptune PMUP or similar rated pump (low flow high head) or use a peristaltic like the BRS 50ml/min which can use the 1/4" on that line without trouble. For the saltwater you are going to need a 3/4" line unless you want to spend $500 on a pump. Even then the pump you have won't work as even 50 gal/hour will reach the 12' head capacity of that pump and that will take foreeeeever. You want something in the mag 12 class of ratings to fill 5 gallons a minute or mag 24 to reach 10 gallons a minute.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  4. zombie

    zombie Barracuda M.A.S.C Club Member

    Another option worth considering if you happen to have an apex. get a DOS and do automatic water changes for the saltwater. You can use the existing 1/4" line and save 100-150 not buying another pump, so the sticker price is more worthwhile.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  5. zombie

    zombie Barracuda M.A.S.C Club Member

    For ATO yes (though masterflex are ungodly expensive so BRS 50ml/min is much better option). For saltwater, I wouldn't recommend using a $1500 pump to do a 30 gallon water change in several hours. At that point you could buy an apex and a DOS have everything automated and still have money left in your pocket.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  6. Balz3352

    Balz3352 Marlin M.A.S.C Club Member

    I wonder duty for dos at that length and head. Or a brs for that matter. Most people don't but masterflex new. So your 1500 tag is off.
     
  7. zombie

    zombie Barracuda M.A.S.C Club Member

    5000 gallons at 18' head for the DOS motors and 500-1000 gallons before head replacements depending on head and speed per Neptune testing. Not sure on the BRS pump but likely a quarter of the DOS ratings.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  8. Dr.DiSilicate

    Dr.DiSilicate Kraken M.A.S.C Club Member

    I'd say you need a 3/8" or so line if you can swing it... And the pump you have may work better. How are you draining the water? How dig of a water change are you doing? Have any pictures of the set up as that may help...

    I have a master flex pump running my calcium reactor. I paid less than 200 bucks and it runs 24/7. I'm not sure it would work for a quick water change situation.


    Sent from my iPad using Tapatalk
     
  9. SynDen

    SynDen Shark Staff Member M.A.S.C. B.O.D. M.A.S.C Club Member

    Ya 1/4 will work great for dripping the water to the tank, but agree that you need to increase the pipe size to a minimum of 3/8 and likely would do best with 1/2" or even 3/4". The 1/4 line may very well burn out your pump as its trying to work harder then it needs due to the small line. Either switch the pump to a peristaltic pump for a drip/continuous water change, or change the pipe size to fit with the pump.
     
  10. zombie

    zombie Barracuda M.A.S.C Club Member

    I've ran the calcs personally (though I made assumptions about number of bends). 3/8 will get less than 20 gal/hour, 1/2" less than 35 gal/hour, and 3/4 less than 50 gal/hour with the current pump.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  11. dweeb

    dweeb Copepod M.A.S.C Club Member

    Appreciate all the good advice.

    120g display (and 40g sump) are in a living room, with no drain close and no way to put any other major equipment in.

    My RODI system is downstairs, about 40 feet horizontally and 8-9 feet height distance. I think it's about 50 feet or more of 1/4" line.

    When I set that up, I ran two 1/4" lines -- one for ATO (freshwater from RODI), and the other for saltwater. I had to drill holes (in a very nice hardwood floor, which made me wince).

    I can't do a continuous water change since I drain the DT/Sump first (I run a garden hose with PVC U hook into the tank with the other end in a small sink across the room and do the standard "suck and cough" suction drill), then add the saltwater.

    I'm doing 25-28 gallons at a time.

    I already reached my wife's limits by running the two 1/4" lines across a room downstairs and drilling the holes.

    I could make the hole a bit bigger for the saltwater line, and run 3/8".

    I already have an Apex set up, and a DOS in the box. But can't run that for water change since I have to do the drain before saltwater fill.
     
  12. Balz3352

    Balz3352 Marlin M.A.S.C Club Member

    Man you must have a lot of equipment in your stand! Shoot stuck with 2 holes hmm. I cant really think of a realistic way to do auto waterchanges
     
  13. zombie

    zombie Barracuda M.A.S.C Club Member

    You don't need to drain before fill with the DOS. They can be done simultaneously and you can run the drain line into the drain in your basement.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  14. dweeb

    dweeb Copepod M.A.S.C Club Member

    I can't add another line. I COULD change to a bigger line.
     
  15. zombie

    zombie Barracuda M.A.S.C Club Member

    You could always add another 1/4" line by saying to the wife "I already drilled two holes, and if I drill one more right next to the others or make it a little bigger we won't have to worry about me spilling saltwater on the floor or get any in my mouth ever again"

    You might be an engineer if...You have no life and can prove it mathematically.
     
    dweeb likes this.
  16. dweeb

    dweeb Copepod M.A.S.C Club Member

    To be clear, I am not trying to set up auto water changes, since that is a bit too steep a hill to climb.

    The pump I used still pumped the water (20g I think) in about 40 minutes. It was coming out of the line (into the sump) with a LOT of pressure, though.

    I may just go to a 3/8 or (ack) 1/2 inch line.

    Zombie, what pump would you suggest then?
     
  17. zombie

    zombie Barracuda M.A.S.C Club Member

    Mag 12 or mag 24 class. Something in the 15' head range and 1000 gal/hr range with no head.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  18. zombie

    zombie Barracuda M.A.S.C Club Member

    And don't bother with 3/8, 1/2 is the bare minimum if you want it to be done in less than 20 minutes.

    You might be an engineer if...You have no life and can prove it mathematically.
     
  19. dweeb

    dweeb Copepod M.A.S.C Club Member

    Doesn't bother me for it to take an hour.
     
  20. jda123

    jda123 Barracuda M.A.S.C Club Member

    Get a powerful Good pump and reduce it down using quality fittings. Mag Drive, Laguna, Fluval, etc.

    I have a whole pile of mags that you can borrow to try if you promise to bring them back. I am in Longmont.

    When inside diameter is smaller than the output of the pump, head usually goes up quite a bit... a maxijet with 3' head can push water up 10 or 12 feet with RO line... however, it can lead to premature pump failure.
     

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