nathanp0515
Member
How do overflows work? What are they exactly?
How do overflows work?
- Thread starter nathanp0515
- Start date
belothsurf
Member
I have a cpr HOB overflow. Like Kip said, the concept is more complex, but they are virtually maintenence free, although they are a little loud, just a faint gurgling noise, not bad, but noticable.
razoreqx
Active Member
I hope this post will explain the HOB overflows.
These devices are fine if your pumping enough water through them for the rating the manufacture suggested for the unit. In other words, you wouldnt want to use a 700g per hour HOB overflow on a 20g tank. You will have problems with to much flow for the tank and a hurricane type effect in the tank If you run the pump required for the unit.
If you use a smaller pump which is under rated for the unit you will have problems with the U tube filling up with air bubbles and breaking the seal... which will flood the room
I'll explain the "U" tube more in detail below.
Picture one shows the internal collection cup and the external piece. The internal collection cup has groves cut into the cup to allow water to overflow into the collection cup. You can adjust this internal collection cup up or down to get the water level you wish to maintain in the display tank.
If you notice both ends of the "U" tube are submerged underwater. This allows the pump to be turned off without breaking the seal inside the U tube.
To fill the "U" tube you would first fill the external box with water up to the level of the "U" tube. There is a small chamber on one side of the External box which allows water to pool before flowing over into 2nd part of the external box.
The 2nd part of the external box has the purferated PVC pipe with usually a sponge covering to help keep the holes in the PVC from becoming clogged. This allows flow of water to exit the collection device and drain down to the sump or wet/dry unit.
These devices are fine if your pumping enough water through them for the rating the manufacture suggested for the unit. In other words, you wouldnt want to use a 700g per hour HOB overflow on a 20g tank. You will have problems with to much flow for the tank and a hurricane type effect in the tank If you run the pump required for the unit.
If you use a smaller pump which is under rated for the unit you will have problems with the U tube filling up with air bubbles and breaking the seal... which will flood the room
I'll explain the "U" tube more in detail below.Picture one shows the internal collection cup and the external piece. The internal collection cup has groves cut into the cup to allow water to overflow into the collection cup. You can adjust this internal collection cup up or down to get the water level you wish to maintain in the display tank.
If you notice both ends of the "U" tube are submerged underwater. This allows the pump to be turned off without breaking the seal inside the U tube.
To fill the "U" tube you would first fill the external box with water up to the level of the "U" tube. There is a small chamber on one side of the External box which allows water to pool before flowing over into 2nd part of the external box.
The 2nd part of the external box has the purferated PVC pipe with usually a sponge covering to help keep the holes in the PVC from becoming clogged. This allows flow of water to exit the collection device and drain down to the sump or wet/dry unit.
razoreqx
Active Member
To fill the "U" tube you insert a small piece of air hose tubing and suck the water over the "hump" of the U tube. Water will start to flow on its own. Make sure you get all the air bubbles out of the "U" tube as these can build up over time and cause the tube to fail resulting in a flood.
There should be a fill line on the wet / dry which gives you an idea how high the water should be. Once you get the water flowing in the U tube and into the wet / dry you want to then start the pump. Everything should flow.
If the display tank starts to overflow the groves on the collection cup portion of the overflow then the water pump is over pumping and you need to cut power back or get a smaller pump.
If the pump pushes to much water out of the wet /dry unit and starts to shoot air bubbles into the display tank you need to allow more water to flow into the wet / dry. this can be done by lowering the internal collection box allowing water to fall into the collection cup quicker. Note your water level will drop in the display tank. You can also add more water volume to the sump if you dont want the water level lower in the display tank from lowering the collection cup.
AFter this has been running and the water levels have adjusted to a "running" level.. (meaning they dont change anymore) you need to test the failover portion of the system.
The return line from the pump has a hole in the end of the tube right before the point where water shoots out into the display tank. This hole should be just at water level or above it.. This hole allows water to keep from flowing back down the return line when the power to the pump is gone. This will prevent your tank from emptying into your wet / dry via that route.
There should be a fill line on the wet / dry which gives you an idea how high the water should be. Once you get the water flowing in the U tube and into the wet / dry you want to then start the pump. Everything should flow.
If the display tank starts to overflow the groves on the collection cup portion of the overflow then the water pump is over pumping and you need to cut power back or get a smaller pump.
If the pump pushes to much water out of the wet /dry unit and starts to shoot air bubbles into the display tank you need to allow more water to flow into the wet / dry. this can be done by lowering the internal collection box allowing water to fall into the collection cup quicker. Note your water level will drop in the display tank. You can also add more water volume to the sump if you dont want the water level lower in the display tank from lowering the collection cup.
AFter this has been running and the water levels have adjusted to a "running" level.. (meaning they dont change anymore) you need to test the failover portion of the system.
The return line from the pump has a hole in the end of the tube right before the point where water shoots out into the display tank. This hole should be just at water level or above it.. This hole allows water to keep from flowing back down the return line when the power to the pump is gone. This will prevent your tank from emptying into your wet / dry via that route.
razoreqx
Active Member
Now to test. Just kill the power to the pump. Water should start to fill up in the wet / dry. You should hear a sucking sound as the hole is exposed on the return flow tube from the pump. THis means water is not flowing backwards into the wet /dry.
Both internal and external portions of the overflow should stay full of water to allow the suction from the "U" tube to maintain.
IF the test is successful you should see the wet / dry fill up but NOT over flow. Make sure you allow enough time to this test as it might take a while for all the water to drain from all the systems parts.
Now just turn the pump back on and you are worry free.
Clean the device expecially the overflow internal and external collection areas at least once a month. It is important that this be free of macro algae, detris buildup and other material that could cuase the until to malfunction.
Check the "U" tube for air bubbles at its peek. There should NOT be bubbles there. IF there are you have the flow rate to low for the HOB unit.
HTH explain more about HOB overflows..
Both internal and external portions of the overflow should stay full of water to allow the suction from the "U" tube to maintain.
IF the test is successful you should see the wet / dry fill up but NOT over flow. Make sure you allow enough time to this test as it might take a while for all the water to drain from all the systems parts.
Now just turn the pump back on and you are worry free.
Clean the device expecially the overflow internal and external collection areas at least once a month. It is important that this be free of macro algae, detris buildup and other material that could cuase the until to malfunction.
Check the "U" tube for air bubbles at its peek. There should NOT be bubbles there. IF there are you have the flow rate to low for the HOB unit.
HTH explain more about HOB overflows..
B
bluedolphi
Guest
How careful do you need to be with the water level in the tank?
Do you have to worry about the water level getting too low?
Do you have to worry about the water level getting too low?
B
bluedolphi
Guest
Yes.... I am referring to evaporated water.
So.... at what point are you in trouble with a wet/dry? Can you let the level drop an 1/4", a 1/2" a 1"? When are you going to have a problem. If you leave for a few days... are you going to need to have an autofiller?
This is one of the problems I forsee using a sump system. They just seem WAY too sensitive. Then there is the noise issues, the flood problems, the water damage of the sumps water/moisture being exposed to furniture, heat transfer issues..... and on and on.
I am not sure I get it.
To hide a heater (most are fully submersible and can be easily hidden), and not have a skimmer on the show tank? But instead to have 2" PVC fittings staring the viewer in the face, and black boxes stuck to the insides of the tanks (overflow boxes inside the tank)?
I know they are the cool setup to have now.... but they seem like they are for someone who is going to tinker with them on almost a daily basis.
I am constantly amazed at the messy looking sump set ups that I see in some of the forums. Do the owners actually think that these eyesores are acceptable? I have seen guys/gals with sump tanks all over their viewing rooms, as though they are proud of them. To the point it actually completely draws the attention away from the main tank...... you know..... the one with the FISH in it!?
I work with pumps, autofillers all the time (not the type used for aquariums). Autofillers "f" up quite often.... and they do not tend to hold up over a long time. I can imagine in a salt water environment, they would be failing often.
With an hob pump/filter, all you have showing in the tank is a 3/4" tube dropping down in the tank. The water level can drop a lot without fear. While there is always the potential for flooding, it is pretty much nonexistent. Seems pretty acceptable compared to the above.
I am playing a bit of devils advocate here..... only because I am not sure of going with a sump setup myself. I likely will, but I sometimes wonder why....
So.... at what point are you in trouble with a wet/dry? Can you let the level drop an 1/4", a 1/2" a 1"? When are you going to have a problem. If you leave for a few days... are you going to need to have an autofiller?
This is one of the problems I forsee using a sump system. They just seem WAY too sensitive. Then there is the noise issues, the flood problems, the water damage of the sumps water/moisture being exposed to furniture, heat transfer issues..... and on and on.
I am not sure I get it.
To hide a heater (most are fully submersible and can be easily hidden), and not have a skimmer on the show tank? But instead to have 2" PVC fittings staring the viewer in the face, and black boxes stuck to the insides of the tanks (overflow boxes inside the tank)?
I know they are the cool setup to have now.... but they seem like they are for someone who is going to tinker with them on almost a daily basis.
I am constantly amazed at the messy looking sump set ups that I see in some of the forums. Do the owners actually think that these eyesores are acceptable? I have seen guys/gals with sump tanks all over their viewing rooms, as though they are proud of them. To the point it actually completely draws the attention away from the main tank...... you know..... the one with the FISH in it!?
I work with pumps, autofillers all the time (not the type used for aquariums). Autofillers "f" up quite often.... and they do not tend to hold up over a long time. I can imagine in a salt water environment, they would be failing often.
With an hob pump/filter, all you have showing in the tank is a 3/4" tube dropping down in the tank. The water level can drop a lot without fear. While there is always the potential for flooding, it is pretty much nonexistent. Seems pretty acceptable compared to the above.
I am playing a bit of devils advocate here..... only because I am not sure of going with a sump setup myself. I likely will, but I sometimes wonder why....
evilss
Member
well on my setup, every week i add about 1 gallon of fresh top off water. i also take the 1-2 minutes to clean the cup of my protein skimmer. you have to do water changes with either of the filtration methonds. plus the water in my setup never drops. the level in my wet/dry drops. so you dont have to deal with the low water level look. i do have the overflow in the back of my tank but its clear. so you dont see it to much. plus my coraline is growing on it. makes it harder to see. you do see my 2 returns at the top of my tank but once again coraline is growing on them as well. the hang on the back filters also make the same water running sound just like the overflow boxes do. my overflow box is actually pretty quite. when the water level drops with a hang on filter you actually get more noise of the water dropping further back into the setup. you have to clean the hang on filters and often as you do the wet/dry. but i like to look of just 3 lil things at the top of my water than a big protien skimmer sitting in there, along with that long tube that should stick down far in your tank for good filtration. as far as water movent you still need power heads. i actually hide my powerheads with my live rock. and also about once a month i check my wet/dry to make sure that it will not flood. its a very easy thing to fix to where it will not do it. and i have used the hangon filters in the past. and from my experience with both i would rather have a wet/dry any day. less work, better look, less noise, better filtration. so i hope you take in all the aspects of both filtration methods before you make a decision.
