How to size a pump to your tank

**BenSow** · 04-25-2010, 6:10 AM

Then is t ok if i wanted a 5 turnover rate for my 40gallon and use multiple filters which add up to 200g/hr?

**badspeller** · 11-12-2010, 5:15 PM

im way to new at this for most of that to make any sence but it was cool to find out how big my fish tank is that was way useful, good place to start.

**noledoc** · 11-25-2010, 4:32 PM

Very helpful post. In essence it's volume v height v friction. I hope you high IQs continue to do the important stuff so us ordinary folks can just understand the basics. Thanks!

**Jc1119** · 01-12-2011, 11:11 PM

So, Chompers, since you are the man when it comes to the math invloved in tank-pump sizing help me understand this.....

the tank i want is a glasscages 300 gallon with what appears to be (4) 1 1/2" bulkheads--2 per overflow box. The pump I want is a reeflo super dart gold rated for about 2700-2900gph@6-7 feet head. While discussing the use of the second hole in each overflow box with some of the other members I was introduced to the Herbie style overflow--basically a secondary drain design that reduces the drain splashing volume in the sump. Great idea. Plumb the first drain hole in each box normally and set up the second hole in each Herbie style......but

while researching i ran across this
http://www.wetwebmedia.com/BulkheadFloRateArt.htm

I was concerned about the gph drain flow through 1 1/2" pvc which isnt a problem, but the 1 1/2" bulkhead is. According to the tests the bulkheads will only allow 975 gph to the sump. Times two is 1950 gph which is about 1000gph short.

Since i really want to turn the tank around 10x an hour should I have glasscages cut the primaries 2" to be safe? I could leave the secondary holes 1 1/2" and be good according to the math but i feel i might be missing something (again

!!!)

I only ask because this info did not come from some chart, it was an actual test on various bulkheads and I tend to trust real testing. Thanks in advance!

**CHOMPERS** · 01-23-2011, 10:29 PM

Originally Posted by Jc1119;4789129;

So, Chompers, since you are the man when it comes to the math involved in tank-pump sizing help me understand this.....

the tank i want is a glasscages 300 gallon with what appears to be (4) 1 1/2" bulkheads--2 per overflow box. The pump I want is a reeflo super dart gold rated for about 2700-2900gph@6-7 feet head. While discussing the use of the second hole in each overflow box with some of the other members I was introduced to the Herbie style overflow--basically a secondary drain design that reduces the drain splashing volume in the sump. Great idea. Plumb the first drain hole in each box normally and set up the second hole in each Herbie style......but

while researching i ran across this
http://www.wetwebmedia.com/BulkheadFloRateArt.htm

I was concerned about the gph drain flow through 1 1/2" pvc which isnt a problem, but the 1 1/2" bulkhead is. According to the tests the bulkheads will only allow 975 gph to the sump. Times two is 1950 gph which is about 1000gph short.

Since i really want to turn the tank around 10x an hour should I have glasscages cut the primaries 2" to be safe? I could leave the secondary holes 1 1/2" and be good according to the math but i feel i might be missing something (again

!!!)

I only ask because this info did not come from some chart, it was an actual test on various bulkheads and I tend to trust real testing. Thanks in advance!

I remember that thread. There was a problem in the testing, but I don't remember what it was. And I don't have the brain power right now to go back and figure it out.

Anyway, I skimmed over it and this jumped out at me:

By doing this, a person is “balancing flows” with a false sense of security.

In a nutshell, way too often people try to design a system with "just enough" but neglect a factor of safety. Make sure you have the extra flow designed into your system (go with the 2" plumbing).

The bulkheads that I have dealt with were never the bottle neck in the plumbing system. PVC pipe is sized by the inside diameter of the pipe (let's say two inches for example). The smallest diameter inside a standard 2" bulkhead is two inches.

Horizontal runs are deal killers. Gravity powered flow is awsome in a vertical run but horrible by comparison in a horizontal run. Also, if a system ingests air, it replaces water volume. Therefore, a gurgling system will not flow to the maximum of its potential.

**CHOMPERS** · 01-23-2011, 10:47 PM

Originally Posted by Jc1119;4789129;

the Herbie style overflow

That's a good concept. While MFK was in an information vacuum during its infancy (if it could ever be called that), we slowly evolved to the same concept. In the early days, several of us used ball valves on the end of the plumbing to the sump to "tune" the pipe to the flow of the pump. When the 'in' and 'out' were matched, the system no longer ingested air. When the pipe purged the air inside, the flow would pick up and then it would ingest air again. You would have to keep adjusting it until there was a happy medium. (There was also a problem with the water levels bouncing.)

**Jc1119** · 01-24-2011, 12:31 AM

The horizontal runs are kinda unavoidable for me if I do corneroverflow. I'm looking at the coast to coast setups right now I'm I'm liking that design concept..... Maximze surface skimming great for saltwater systems but an interesting concept for high turnover rate freshwater systems too. IMO

If I were to do a coast to coast overflow there wouldn't be any horizontal runs at all... Straight to the sump. And from what alot of folks have proven a Herbie which is fully submerged siphon moves alot more water than a siphon with air. 1 1/2" would seem to be more than enough in a full syphon hut I kinda like building the system with some depth..... I could see eventually going with a much bigger pump depending on how deep into the pleco world I dive.....

Seems like 2" with Herbie overflows would give me some headroom .....

I like that.....

**freshfishla** · 02-03-2011, 3:30 AM

hey I have an oceanic 175 gallon aquarium with dual overflows. Since I have dual overflows does that mean I should look for twice the power. Also for an African cichlid tank what is the preferred turnover rate. I appreciate any advice.

**Tigz** · 05-22-2011, 3:38 PM

Originally Posted by freshfishla;4854234;

hey I have an oceanic 175 gallon aquarium with dual overflows. Since I have dual overflows does that mean I should look for twice the power. Also for an African cichlid tank what is the preferred turnover rate. I appreciate any advice.

No, unfortunately it doesn't work like that.
If you had needed a single 1.5" pipe, a duel pipe system would need 2 x 1.25" pipes.

**inkslinger** · 05-25-2011, 7:42 AM

I would like to throw out something I had been fighting for a while, I
have a Blue Line 55 HD 1100gph pump with a Nu-Clear 533 an 547
filters , I also had a second line too a Mazzie setup an bottle neck it on the return , This cause me to have 90F 24/7 . Ounce I corrected the bottle
neck the temp drop down to 85F.
The pressure pump had a 1 inch in/out , Should I run a 1-1/2 line going
into the pump? Will this cool it down more, I've remove the second line also
an temp stays at 84F before the lights come on.

My tank is a 110g tank 60x18x24