Question: 3/4" Drain with 1/2" Return, what pump will be good?

[NanoAquatic]

I'm trying to make a small frag tank, so i'm going to drill a 20gallon long with a 3/4" drain with 1/2" return. I did all the acrylic work to my mini 5 gallon sump. What pump and how much gph would i need to pump all the water into the return and to prevent flood on my 5 gallon sump? Don't laugh, i know it's small. Would a Maxi-Jet 1200 do?

 

[masterswimmer]

First, a maxijet is not a pressure rated pump. So no, I would not use that.

Second, how many feet up from the sump is your display tank?

How many feet of pvc (or vinyl tubing) are you running? Any ball valves, 90's, unions, etc?

All these things need to be taken into consideration.

Russ

 

[masterswimmer]

BTW, the pump has no bearing on whether or not your sump floods.

swimmer

 

[OzoneParkGuy]

mag 3 or 5 can use a mag 7 with ball valve to slow the uptake of water into the return so your drain can catch up. Every 1 ft of hard or soft tubing you subtract 100gph as well as for every elbow.

 

[anthony27]

I will help you out if you need help but ozone is correct

 

[masterswimmer]

Every 1' of pvc pipe (or flexible tubing), plus each pvc fitting equals one additional foot of head pressure.

Depending upon how many feet of backpressure you could conceivably use a Mag 12 and not even dial it back. Without the answers to the questions I asked you cannot possibly determine what pump should be used.

swimmer

 

[OzoneParkGuy]

depending upon how many feet of backpressure you could conceivably use a mag 12 and not even dial it back.
Swimmer

+1

 

[DrHarryLopez]

sounds complicated

 

[NanoAquatic]

was all of that even english? lol... jk.

so i'm guessing if my pipe was about 3ft long (3 elbows).. i should be ok with a mag 5

 

[masterswimmer]

was all of that even english? lol... jk.

so i'm guessing if my pipe was about 3ft long (3 elbows).. i should be ok with a mag 5

number of feet from sump bottom to top of tank
+
number of elbows
+
number of bulkheads
+
number of ball valves
+
number of unions
+
number of couplings
=
Total Feet of Backpressure


Example:

4 feet from sump to tank
1 bulkhead
1 ball valve
1 union
1 90 degree elbow
----------------
8 feet of backpressure (also known as head pressure)

With 8' of backpressure a Mag 7 would give you ~300 gallons per hour (gph)

With 8' of backpressure a Mag 9 would give you ~650 gallons per hour


If you can give us the amount of backpressure on the pump you'll be using we can calculate which pump you should use.

HTH,
Russ

 

[masterswimmer]

FYI

The amount of flow 1/2" sch. 40 pvc pipe allows is 420 gph

You need to MAKE SURE your pump will not generate more flow than 420 gph after you calculate the backpressure as described above.

This will determine the exact pump you can use. If you need me to help you select the appropriate pump I'd be happy to help.

Russ

 

[OzoneParkGuy]

could get away with a 5 because of the 1/2" nipple which bottle necks the flow inturn increasing pressure. but i would go with a 7.

 

[NanoAquatic]

3 feet from tank to sump
1 bulkhead
2 135 degree elbow
2 90 elbow

 

[NanoAquatic]

so i'm guessing a mag 5 or 7 :x ... in a 5 gallon sump lol

 

[OzoneParkGuy]

seems like alot of pump but it isn't because of the equipment like elbows and plumbing.