DIY plans for Coil Denitrator

howdy20012002 · #1 01-16-2007, 12:20 PM

I actually built a coil denitrator out of parts I got from home depot.
I will post pics and details today.
thanks
Neal

howdy20012002 · #2 01-16-2007, 05:26 PM

As I understand it, the concept behind a Coil Denitrator is a simple one.
Basically, as the water travels through the coiled air hose, it loses the oxygen content within it. This unoxygenated water and environment allows for bacteria, which just happens to have an appetite for nitrates, to grow in the container(in about 4 - 6 weeks). Thus, as the water travels through the media where the bacteria is, it loses the nitrate content and then exits back into the tank nitrate free or at least with a lowered nitrate content. it can take a few times for the water to go through the denitrator to lose all nitrates.
if anyone wants to add anything or correct anything please do.
I am far from an expert in this matter.

howdy20012002 · #3 01-16-2007, 05:49 PM

the material needed:
1 - 3 foot piece of 3 inch black pvc
1 - 3 inch cap
1 - 3 inch to 4 inch toilet flange
3 - 25 foot 1/4 inch airline ( i used a the more rigid type)
4 - 1/4 inch quick connect union
1 - 1/4 inch shut off valve
1 - 1/4 inch quick connect valve
material for growing bacteria - (bio balls and ceramic rings)
1 - 4 foot piece of 1.5 inch pvc
duct tape
pvc glue
teflon tape.

andresont · #4 09-12-2007, 02:58 AM

Quote:

Originally Posted by howdy20012002

the material needed:
1 - 3 foot piece of 3 inch black pvc
1 - 3 inch cap
1 - 3 inch to 4 inch toilet flange
3 - 25 foot 1/4 inch airline ( i used a the more rigid type)
4 - 1/4 inch quick connect union
1 - 1/4 inch shut off valve
1 - 1/4 inch quick connect valve
material for growing bacteria - (bio balls and ceramic rings)
1 - 4 foot piece of 1.5 inch pvc
duct tape
pvc glue
teflon tape.

How about using wider then 3” Black PVC ? say 5” pipe?
Then we can roll more tubing say 30% more, and leave it on the smaller diameter 1.5" PVC pipe. Now you don’t have to remove the inner 1.5"PVC pipe, just insert it together with air tubing inside the wider then 3” PVC and drop the bio balls or coral rubble inside.
So this is pretty much the same thing except now we have more uniform air tubing distribution with possibility of longer water travel within same hight unit just wider and one does not need a second person to unload the air tubing.
Maybe if cost is still low this can be done in even shorter but wider unit that will fit under the aquarium stand.
What do you think guys?

Der_Iron_Chef · #5 09-12-2007, 03:08 AM

I think perhaps the only problem with a shorter/wider denitrator is that the water wouldn't have as much contact with the bio balls, which is where the real denitrifying occurs (if I'm understanding it correctly).

andresont · #6 09-12-2007, 03:43 AM

Quote:

Originally Posted by Der_Iron_Chef

I think perhaps the only problem with a shorter/wider denitrator is that the water wouldn't have as much contact with the bio balls, which is where the real denitrifying occurs (if I'm understanding it correctly).

Ok, how about same hight but wider?

howdy20012002 · #7 01-16-2007, 05:50 PM

Part 1.
The most difficult part of this project is to drill and thread the pvc cap for the 1/4 inch valves.
You will need the appropriate tap and die set (or talk really nicely to someone that does) to thread the holes on the cap.
After you have drilled and threaded the holes, you then put teflon tape on the threaded ends of the quick connect valves and tighten them into the drilled holes.
Unlike shown in the picture, have the 1/4 valve (the one without the blue shutoff valve) on the inside of the cap, not on the outside.

A couple of things,
make sure you don't overtighten the valves. Being that everything is made of plastic, it wouldn't take that much to break something. it should be snug..but don't reef on it.
as well, wrap the teflon tape a few times around the thread as this will help stop leaks and make sure that things are waterproof.

howdy20012002 · #8 01-16-2007, 06:28 PM

Step 2
I basically had to come up with a way to connect the hose to the inside of the cap so that it would stay connected
I tried to glue it together with crazy glue, but apparently air hose and the quick connect valves don't like each other.
what I came up with was have the valve on the inside of the cap instead of the top of the cap. I then drilled out just enough of the inside of the valve so that the 1/4 inch airhose could go completely through the valve and out the top end of the cap.
I basically used a 1/4 drill bit and just slowly drilled out the valve.
Make sure that you go in the direction that the air hose will be going so that it dosn't push out the inside of the valve...IE, go in the direction of the valve.

howdy20012002 · #9 01-16-2007, 06:44 PM

Step 3
I used a more rigid airline so that I could have more control of where it was going. You could probably use a more flexible airhose if you wanted. However, I was concerned that by using a more flexible airhose, it would just all end up in the bottom of the tube and not spread out along the entire length of the pvc pipe.
Apparently from what I have read on the net, it is recommended that you have 75 + feet of airline for the oxygen to be removed from the water.
therefore, I bought 3 x 25 feet pieces of the 1/4 inch airline and connected them together using the quick connect unions.
I then duct taped one end of the airhose to the 4 foot piece of 1.5 inch PVC.
I then started to wrap it around the pvc pipe, until I had the 75 feet of airline wrapped around the 1.5 inch PVC.
once done, I taped the other end to the pipe so that I could let go and it wouldn't all unwrap. I then let this be for a few days so that the airline would actually form to the shaped that I wanted, which is just slightly smaller than the inside diameter of the 3 foot long 3 inch PVC pipe.

howdy20012002 · #10 01-16-2007, 07:18 PM

Step 4
After a few days to allow the airline to adjust to the new shape, it is now to time for the next step.
the next thing that needs to happen is to connect the toilet flange to the 3 foot 3 inch PVC pipe.
this toilet flange acts as a stand for the tube and allows it to stand on its' own.
the trick is to have the air tubing down at the bottom of the tube.
What I did was have the 4 foot piece of pvc with the airline wrapped on it inside the 3 inch PVC pipe and then undo the duct tape on the end of it so the end of the airline inside the 3 inch pvc. I then glued the flange onto the end of the 3 foot 3 inch tube. ensure you turn it abit so that the PVC glue settle properly.