GPH Test?

an411

New member
I was wondering if there was any way to test how many gallons are being pumped through my system. Meaning from the overflow box to the sump back to the display tank. I just want to make sure that I am getting the max turnover in my tank.
 
There are flow meters available, but they're generally either really small range, or otherwise awkward to use on a reef tank.

The simplest way would be to measure the volume pumped in a given amount of time. This would be tricky when the system is established and running, but you could rig it so the drain to the sump is draining to a bucket instead - don't change anything else in the plumbing, or you may throw off the test. Depending on your setup, this might actually not be that difficult - if you have flexible hose for your drain, you could just set the bucket next to the sump, then cover the end of the hose with your hand and quickly move it to the bucket.

Mark a line in the bucket corresponding to one gallon, and time how long it takes to fill the bucket to that level.
 
... what der_wille_zur_macht said, but you might want to put the bucket at the same height as your tank's return.
If you put the bucket right next to the sump, there will not be the head of water that there is to return the water to the tank.
If you could put the bucket at the same height as the tank's return, that should give a bit more accurate of a reading.

HTH
 
fwiw An411, the actual number isn't as important as getting the right amount and type of flow. This is why you get a wide range of turnover rates from one tank to another. As long as you are ballparking it close enough, you should be fine.
 
Papagimp isn't more better I mean you don't want things blowing away in the tank. But I thought the more turnover the better.
 
well your tank->overflow->sump->return->tank flow is usually going to be only limited by how much water you can pump back up into your tank from your sump.. if your pump is flowing more than your overflow you need to either put a ball-valve in its way or get a higher-flow overflow... otherwise your display will overflow onto the floor ;)

ANYWAY.. since your return pump should really be the bottleneck in the system, just stick a gallon jug onto the return, hopefully you can hold it at water level to account for proper head loss.. turn the pump on and start counting.. once it's full calculate from there.
 
also, you dont want all your turnover coming from one source... you probably only want about 5x going through the sump and the rest coming from powerheads or a closed loop system.
 
dwl, I'm talking about measuring the flow on the drain line running TO the sump, not the return line running FROM the sump to the display. Since the drain line is powered by gravity and sucks enough air to always be 100% balanced with the return line, you can measure it without interfering with the actual flow rate. On the other hand, the return plumbing is fighting gravity, and hence any change at ALL to the return plumbing will affect the flow rate - so you do not want to measure the flow rate by altering the return, otherwise you'll throw the test off.

an411, there's a whole universe of things I don't know. Fortunately for me, I've managed to already make many of the mistakes people make in reefkeeping, and/or have faced the problems people typically face. Trust me, there were a lot of failures on my part in the process of learning these things! :)
 
ok I got what you guys are telling me to do. I am going to have to check this as soon as my new pump gets in and I install it.

The reason I am asking this is I want to get everything running perfect or I should say efficiently so i can find my optimal waterlevel for my sump so I can install an auto top off.
 
<a href=showthread.php?s=&postid=10466963#post10466963 target=_blank>Originally posted</a> by XSiVE

ANYWAY.. since your return pump should really be the bottleneck in the system, just stick a gallon jug onto the return, hopefully you can hold it at water level to account for proper head loss..

Again, you don't want to measure flow on the return. Even though the return pump/plumbing IS what determines flow, as you've stated, it's also the case that altering it at all will ALTER the flow produced, so you won't really be measuring the flow in your system in an unaltered state.

Even trying to measure by holding a container at water level wouldn't be effective, since the bends and turns in the plumbing can cause as much head loss as the actual vertical distance pumped, if not more. So unless you were holding the container inside your tank to catch the water as it came out of the unaltered return plumbing, you'd be altering the measurement. And of course holding a container around the unaltered return opening is not possible when the tank is running.

However, the drain line running to the sump is just a gravity fed mess of air and water, with the volume of water always being 100% equal to what the return pump is pumping. Hence, you can measure the flow rate there without effect on the result.
 
XSiVE Yeah I know that all of my turnover should not come from the sump I also have 2 Hydor Koralia 4's helping with my turnover rate.
 
<a href=showthread.php?s=&postid=10467000#post10467000 target=_blank>Originally posted</a> by an411

The reason I am asking this is I want to get everything running perfect or I should say efficiently

Honestly, you don't really need to know the flow rate in order to optimize it, since it's already common knowledge as far as what is restrictive to flow.

Firstly, make sure you're using the correct pipe sizes for your pump. It should come with a spec to tell you what diameter to use for the input and output. Keep in mind that if you split the output, you can't always bump down to a smaller pipe size, as some people tend to do. The critical measurements are the cross-section of the pipe and the surface area of the wall inside it. Cutting the diameter of the plumbing in half is equivalent to quartering the cross section. The simple way to think of this is that two 1/2" pipes are MUCH smaller than one 1" pipe. So if you split the output, keep the pipe size the same - unless you split it many, many times.

The other critical item is bends and turns in the piping. A 90 deg. bend is your worst enemy! Unfortunately, many people plumb several of them into their return piping. Instead, consider using two 45's right next to each other, which is less restrictive. Also, plan the plumbing beforehand to require as few bends as possible.

Do those things and your system will be optimized, regardless of whether or not you actually know the flow rate. Though, measuring it would definitely be a really fun experiment.
 
Yeah I have 2 90's on my return plumbing they were unavoidable unless I used flew tubing.
 
<a href=showthread.php?s=&postid=10466960#post10466960 target=_blank>Originally posted</a> by an411
Papagimp isn't more better I mean you don't want things blowing away in the tank. But I thought the more turnover the better.

All relative to the species you are keeping. Granted the ocean as massive amounts of current, we just have a severely difficult time duplicating that type of flow in a home aquarium, so more flow isn't always better. Correct flow is however. Such as utilizing the Tunze or Koralia power head vs. using more laminar ph's like the maxijets. I had more flow when I was using maxijets, but the current in the tank still wasn't right, I went less flow with the koralia pumps, but now the tank looks more appropriate. The flow is much more turbulent where it needs to be and none of my froggies are getting blasted from a single side only.
 
I guess Its hard to determine that now if my flow is good until I get some stuff in there. The powerheads seem to be giving off a good amount of flow. they are giving off water aggitation on the surface and I can see the sand moving very slightly so it seems to be covering most of my tank.
 
<a href=showthread.php?s=&postid=10467007#post10467007 target=_blank>Originally posted</a> by der_wille_zur_macht
Again, you don't want to measure flow on the return. Even though the return pump/plumbing IS what determines flow, as you've stated, it's also the case that altering it at all will ALTER the flow produced, so you won't really be measuring the flow in your system in an unaltered state.

Even trying to measure by holding a container at water level wouldn't be effective, since the bends and turns in the plumbing can cause as much head loss as the actual vertical distance pumped, if not more. So unless you were holding the container inside your tank to catch the water as it came out of the unaltered return plumbing, you'd be altering the measurement. And of course holding a container around the unaltered return opening is not possible when the tank is running.

However, the drain line running to the sump is just a gravity fed mess of air and water, with the volume of water always being 100% equal to what the return pump is pumping. Hence, you can measure the flow rate there without effect on the result.

I misinterpreted what you were suggesting... and didnt think you were talking about doing it with the return pump on.. cuz if you started with a higher water level than normal in the tank or something then you would just be measuring the flow of the overflow, not the return ;) I see what you meant now.
 
der_wille_zur_macht,
I obviously did not understand that you were talking about the tank drain side.
That does indeed make sense. Didn't mean to step on any toes.
 
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