Why is my Overflow Box not going at its advertised rate?
- Thread starter CrAzYNeSs
- Start date
I would either buy another overflow or maybe call the company and ask what the deal is. Or you could try buying an inline flow meter and seeing how fast everything is actually working.
just take a 5 gal bucket and a stop watch and measure the flow its possible the pump is pumping way over rated i had a tetra watergarden pump that was rated for 1000gph at 0 head but when i measured it at 5 ft head it was 1250 gph so just an idea
yogurt_21;3609977; said:
In that link Chompers does state that a 1" diameter pipe has a 600 gph maximum... he also states that is at a 9 inch vertical drop.
Since the water level of the Overflow box is not 9" lower than the water level of the aquarium... this minimum 9" vertical drop is not achieved... thus the 600 gph maximum will not be reached...
The practical example of this concept... Think about when we are siphoning from a tank to a bucket... if we raise the bucket so it's surface is just slightly lower than the aquarium's surface, the siphon is very slow... if we lower the bucket, the siphon goes faster...
Since the water level of your Overflow box is only slightly lower than your aquarium's water level, the siphon will be quite slow.
I think the simple answer to why your unit is not functioning to the rates it is advertised to... is that truth in advertising is dead... Manufacturers commonly manipulate the details so that they can boast higher claims than the user can actually achieve.
When was the last time you bought a filter that was rated "up to 400 gallon tank"... and it could actually offer adequate filtration to a 400 gallon tank by itself...
I dont know, nc_nutcase... I've heard plenty of people using these & most of them gave positive reviews. I'm leaning more towards the pipe size being too small after the bulkhead & the pump pushing more water than its rating suggests. OP-where is it overflowing? Is it the tank or the overflow box or both? If the tank is overflowing but the box has a normal water level, I would blame the box, but if the overflow box itself is also overflowing, then I would say your pipe is not allowing enough water out of the box causing both to overflow.
JakeH;3611084; said:
Well, according to Chompers thread, a 1" pipe requires a 9" vertical drop to siphon at maximum capacity...
According to basic principals of a siphon which any of us can easily verify... when two water surfaces are very close to the same level, the siphon runs slow... when the distance betwen the surfaces is increased, the siphon runs faster...
In the Overflow box design used here, the surfaces are very close to the same level... and are MUCH less than 9" apart... therefore according to science, the 1" diameter pipes will not flow at maximum capacity...
I would suggest that the people that give them positive reviews did not notice or realize that they are running considerably below the advertised maximum capacity...
JakeH;3611084; said:
Outside of your post here, I've never heard of anyone suggesting their pump performed above it's rating under head pressure. Per the pumps design, the flow rate will decrease under head pressure... and it seems extremely unlikely that a manufacturer would make the blunderous mistake of underrating their pump...
Is it possible there was a proplem with your flow meter? I don't want to be confrontational and I'm not insisting you are wrong, I'm just pointing out that your experience conflicts with what is otherwise regarded as "fact".
JakeH;3611084; said:
It appears to me that the top rim of the box will be slightly higher than the top rim of the aquarium... Therefore it will be impossible for the overflow box to actually spill over the rim since it is being fed by a siphon from the tank.
You are right in showing conern for the overflow box's drain being to small... The smaller it is, the higher the water level in the overflow box, thus the slower the siphon between the aquarium and the overflow box will be...
but until the difference in water levels between the aquarium and the overflow box reaches 9" (which it cannot ever be per design of the box) this overflow box cannot perform at it's rated maximum...
nc_nutcase;3611438; said:
I think I see what you're saying here and I think I see it a bit differently. This design of overflow box uses a U-tube siphon to go from the tank to the other side of the box and then the two pipes act like drains to move the water to wherever you want it to go. The U-tube piping that does the siphon portion is actually two 1.25" intake tubes which if we still go with chompers should be about 937.5 gph each if they have a 20" vertical drop. Now obviously they don't have that drop but I would think they should be able to at least keep up with more then 1400 gph. But I do agree it probably won't flow as fast as they claim. I'm not trying to be confrontational or anything I actually want to know what you think. I feel like this overflow should be working.
Also, from my understanding it should have two 1.5" drains. Not two 1" drains. Which basically would mean the limiter in the system would be the syphon portion. Are you sure everything is set up propely/they didn't send you the wrong one? The 1,000 GPH one that's a step down from the 1,600 GPH one has two 1" drains....
