gph for overflow siphon??????

[mistermismatch]

i have just built a sump for my 55 and a DIY pvc overflow. im wondering what is the gph my overflow will put out if its made with 3/4" pvc??? my return pump puts out 581 gph. am i correct in assuming the gph between the pump and the siphon have to be similar???? everythings built i just have to put it together and i have ball valves in line to adjust flow where needed on either end. thanks!

 

[David S]

I think a 3/4 overflow is around 600gph,you have to allow for the head the pump needs to pump as well which will drop the rate down slightly.

 

[mistermismatch]

so you think with the flow fully open i should be ok????

 

[David S]

I would think so but you could plumb a Tee into your return and plumb back into your sump with a valve on it so you can easily adjust the flow just to be on the safe side.

 

[mistermismatch]

would i put the tee before or after the valve. im assuming before right?

edit.
never mind i think i got it... would it go:
pump >>tee>>
>>route 1:tank
>>route 2: valve>>sump

 

[abdhalim2]

if 600gph overflow and 581gph return, IMO its not enough...its due to the head loss...

 

[mistermismatch]

if 600gph overflow and 581gph return, IMO its not enough...its due to the head loss...

im sorry im not familliar with the term "head loss". im new to the whole sump thing. thanks for everyones patience

 

[abdhalim2]

its depends on how many Tee or L pipe/elbow from your return to your tank.....here is the link to calculate about it...its from Mr X before....
http://www.reefcentral.com/calc/hlc2.php

 

[six2sevenproductions]

im sorry im not familliar with the term "head loss". im new to the whole sump thing. thanks for everyones patience

Your pump is rated at 581gph. As the water travels through the pump upwards, that number will decline for every foot in which it travels.

If it takes 4 feet to go from your sump on the floor up to the top of your tank, that that is a 4 FOOT HEAD LOSS. you have to calculate how much water is being pushed after the four feet. so after 4 feet it might only be pumping out something like 420gph (did not do the math).

The GPH will also decrease for every turn, ball valve and check valve you add.

 

[David S]

Ok,The 3/4 pipework will work with the return pump you have because of headloss and restristions others have pointed out.
Here is a quick example of the valve i was talking about.
http://www.aquariumadvice.com/forums/members/22825-albums1212-picture8406.png

I think you should upgrade your overflow to 1 1/4 pipe to get you over 800gph and then upgrade your pump.
But if money is tight htan what you have got will do

 

[cmor1701d]

A 1" gravity drain will be about 600 gph. A 3/4" will be considerably less, though I don't have the number handy. You really need to use the Bernoulli equation to calculate the actual number.

Yes, you need to match a pump to the overflow. Use a valve on the return line to cut back the flow if necessary.

Someone already has you covered on the head loss aspect.

 

[David S]

A 1" gravity drain will be about 600 gph. A 3/4" will be considerably less, though I don't have the number handy. You really need to use the Bernoulli equation to calculate the actual number.

Yes, you need to match a pump to the overflow. Use a valve on the return line to cut back the flow if necessary.

Someone already has you covered on the head loss aspect.

Cmor I have the eshopps 800 which has a 1" u tube and delivers 800gph which is why i would have thought 3/4 would do with the pump he has
A 3/4 gravity pipe will deliver 660gph
Here's where I got the flow rates from
http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

 

[mistermismatch]

thanks alot everyone. i have it all set up and the flow rates almost equal. just having trouble pinpointing the exact amount to turn the valves to equal it out exactly. im marking my waterline in the sump and it varies slightly every hour or so, causing me to have to adjust the valve ever so slightly. i guess persistance and patience will do the trick here


edit... wow just realized how repetitive this comment was lol

 

[cmor1701d]

I see they added that gravity feed on that site. I've always gone by the 600 gph for a 1" overflow, but I may have been wrong.

@mistmatch: You lose water due to evaporation in the sump. Are you sure that's not what you are seeing? You need to add RODI water daily to make up for the water lost due to evaporation.

 

[abdhalim2]

i would also said so...its due to evaporation....its either u get a auto top off (ATO) or u can add it manually....u dont need to adjust your valve....just stick with it and do add RO water when its below your mark....

 

[six2sevenproductions]

i have just built a sump for my 55 and a DIY pvc overflow.

What kind of DIY over flow do you have. I have seen his before where people do not have an over flow at all but simply have water being siphoned out of the tank into the sump with pvc. In this case the return pump needs to match the exact amout of water being siphoned out. When it does not match the water level in the sump rises and falls depending on the adjustment. The people spend hours turning ball valves to match the flow.

Is this your situation?

 

[David S]

Do you have any photo's of your setup,you shouldn't need to keep adjusting the valve,how have you made your syphon,if you turn off your return pump water from the dt will keep flowing down to your sump until an air break,make sure you drill 2 holes in your return pipe just below water level in dt,does your overflow box hold the syphon when return pump is off.

 

[mr_X]

What kind of DIY over flow do you have. I have seen his before where people do not have an over flow at all but simply have water being siphoned out of the tank into the sump with pvc. In this case the return pump needs to match the exact amout of water being siphoned out. When it does not match the water level in the sump rises and falls depending on the adjustment. The people spend hours turning ball valves to match the flow.

Is this your situation?

that won't work....there are too many variables to consider. i hope that's not your situation!

 

[cmor1701d]

I hadn't considered that possibility. As Doug stated, there are too many variables at work to make that situation stable.

 

[mistermismatch]

DIY Overflow Using Only PVC Pipe (DIY OVERFLOW PROJECTS)

its similar to this except with a valve before the water hits the sump. the return has a tee with a valve to return extra water to the sump to adjust the return flow. i dont think its evaporation. the water level changes too quickly for that to be an option. for instance: i marked a line at the top of the return chamber last night and this morning the water was barely over the top of the pump and it was making a slurping sound.