tank piping to sump

[scooter blenny]

hi, someone pls advise me on how to calculate water flow, pipe dimension from the tank to the sump and what capacity pump to use for the return.

i do not want my tank or sump to be flooded or run dry.

thanks

[Ian]

What size is your tank and your sump?

[islander]

usually for marine tanks,the turnover rate is around 3-5times the capacity of ur tank,meaning if ur tank is 300liters, u need a circulating pump of eg..4(approx)x300litres=1200 litres per hour.what u can do is putting a ball valve just after the main tank outlet-to control the flow,if its splashing,reduce it.then another ball valve after the pump discharge to control the flow to the tank.

remember,what u need to create in a marine tank is a high flow not high pressure so choose the pipings that are bigger that give u more flow instead of small pipings which create high pressure.

water pumps are mostly centrifugal pumps so don worry about ur water from the sump to 'backflow'.some ppl install check valves affter the pump discharge but tis is deemed unneccessary cos if the flapper fails,hmmm...u will be flooding ur sump.DUN TRY!IT HAPPENED TO ME!

the two ball valves(one outlet from main tank,one after the pump) can control when u need additional or less flow.

[rockfish]

erm ... lets see .. have to let me recall my fluid dynamics..

u can calculate backwards..

state ur tank volume first .. i.e. 300L

then state ur turnover rate per hr.. lets say .. 4 times/hr

calculate the volume flow rate first...

300 x 4 = 1200L/hr

then convert the vloume flowrate into L/sec..

1200 / 3600 = 0.333 L/sec

or 333 ml/sec

so 333 ml supposed to pass thru ur pipe per sec

1 ml = 1 cm^3

gravity = 9.8 m/s^2

then the speed = accel x time

speed = 9.8 x 1 sec

= 9.8m/s

= 980 cm/s

divide the volume flowrate by the speed .. u will noe the diameter of ur pipes..

example: 333 / 980 = 0.34 cm^2

34 mm^2 is the area of ur pipe...

then the final step is wat most of us noe...

circle area = pi * r^2

r^2 = area/pi

r = sqrt(area/pi)

so ..

r^2 = 34/3.142

r = sqrt(34/3.142)

r = 3.3mm

so diameter is 6.6 mm...

so ur pipe have to be more or less 6.6mm dia .. understand ..??

just follow the step .. and change the values to ur own .. should be able to do it .. i guess this is detail enough ..

if still dun understand .. PM me ... i enrol u to my tution class ... haha

i charge very cheap .. keke ... $50 per min ... hahah

[ah^siao]

wah xian diao.. some one showing off physics..

where are the experts?

no need calculate till lidat la....

abit kua zhang

[rockfish]

chey... he wants to noe mah so i tell him lor ...

as long as ur pipes is larger than that will be okay wan lah ..

and that calculations is really easy mah ..

[dradttg]

Aiya calculate until so jia luk. Go to Reef Central and use the calculator there. It even tell you the size of you overflow box and diameter of pipe.

Thank bro SharkBait for showing me.