Denitrator.

[handb94]

So I am making a coil denitrator. From the sites where it shows how to build them, they all say it is for saltwater. Can it be used for fresh? I don't see why not. It will still work the same right?

Also, what size return pump should I use? I am thinking no more than 50 gph. I got an old windshield washer pump from work and I am going to wire it to be used in the wall socket. Do you think this will be sufficient? Thanks, Alex

 

[corrado33]

I think it'd work fine for a freshwater aquarium as well. The only problem I see with this is it's effectively taking all of the O2 out of the water. Fish need O2... I'm just sayin. It's a cool idea though.

 

[handb94]

I know. I plan on having 3 air stones to help with that.

 

[ilostnemo]

if you dont mind me asking why do you need a denitrator?

 

[corrado33]

If I'm correct, having something to remove Nitrate would eliminate the need for water changes as the final product of the nitrogen cycle would be removed.

 

[handb94]

nemo I don't mind. corrado pretty much answered the question.

 

[tmcgee]

So in effect you would just have to do top offs? What about built up gunk on the sand bed? I suppose if you have a power head that flows parallel to the substrate surface, it never settles down and then you wouldn't have to do a vac on it.

 

[corrado33]

I think that this is a cool idea, but only in certain circumstances, such as a tank that's hard to access. While yes the nitrate levels wouldn't rise, other chemicals usually removed during water changes would. I don't know what chemicals they are, but I'm sure there are some. Are these chemicals harmful to fish or plants? Who knows... but pretty much any chemical in high enough concentrations isn't good. Plus, the little bacteria that "eat" nitrate don't necessarily just make it disappear, they just convert it to something else. So whatever that "something else" is, is going to build up in your tank unless it's used by another something else.

In response to your original question about return pump size... if I had to make a guess, I'd say that the water flow through this coil is directly related to how efficient it is. Meaning that if it's too fast, the O2 won't have enough time to dissipate and you'll never get the nitrate eating bacteria. I'd try to find some examples online and see what pumps they used.

 

[handb94]

I should have clarified a little sorry. I don't want it to completely eliminate the water changes, just to help. I plan on having a lot of fish and I am not sure how big the bio load will be. I will still vac the gravel bed. I do agree with you corrado.
They say the flow coming out should be a fast drip. I will just have to experiment I guess.

 

[corrado33]

I figured you wouldn't want to eliminate water changed completely.

Anyway, you're probably right about experimenting. You can always get use the Y and ball valve people use when they have sumps. Basically in the output for the pump, you attach a Y. On one Side of the Y you'd have the coil, and on the other side you'd have a ball valve that leads back to the tank (or sump, in the case of a sump). You then simply adjust the ball valve more open or more closed to get the flow you want through your coil.

Also, how do you plan on getting the DC washer fluid pumps run on AC power? I guess you could just buy a 12v adapter and do some simple wiring. Aren't washer fluid pumps loud? Just things to consider. I wonder how much GPH those pumps are. Also, I doubt they're submersible, so you'll have to do an external mounting. And you'll have to find some piping/tubing that'll mount to the pump nicely. (I'd salvage some washer fluid piping from a car). If this works out well, I might have to make a trip to the junkyard.

 

[Viper]

You will still have to do water changes as there are trace amounts of different elements in your water (phosphate, iron, etc....) These don't all exist in equal amounts so when one element runs its course in the current water (i.e. is used up by plants, algae, etc...) there will be an imbalance that occurs. This imbalance will result in the production of algae.

This is my theory on that as I've never used/heard of a denitrator and after reading about it, it makes it sound like a device that allows the aquarist to be lazy. Doing a water change once a week isn't much to ask for.

 

[corrado33]

it makes it sound like a device that allows the aquarist to be lazy. Doing a water change once a week isn't much to ask for.

I was going to say something similar, but I'm too nice...

 

[Viper]

I was going to say something similar, but I'm too nice...

Haha I try not to sugarcoat too many things. Best to tell it how it is when lives are at stake (the fish's of course).

 

[handb94]

Actually corrado that is what I was planning on doing with the Y. I am going to use an old phone charger with the adapter to plug it into the wall. They aren't normally submersible but I can wire it so I can just drop it in the tank. No big deal. I don't think they are that loud. It shouldn't be a problem.

I know viper. I will continue the changes. It's not to make them lazy it is just to help with tanks with big bio-loads.

 

[corrado33]

An old phone charger? I don't know if that'll be enough to power the washer pump. What is the amperage on the charger and pump? If you try to draw too much power out of somethin that's not made to give it, you'll have a fire on your hands.

Ex. My cell phone charger pushes a full 0.7 Amps at 5.1 V. That's really a small amount. Also, is the phone charger 12 V? You could always go to your local electronics store and pick up a DC power source. When I was at radioshack recently I saw a 12 V, 1 or 1.5 amp power source for $25 bucks maybe? Or you could always make one from an old PC power supply. Those'll give you like 10-20 amps or somethin depending on the one you have.

They're really easy to make too, just go to Instructables - Make, How To, and DIY and type in ATX bench power supply. Much like this one... ATX to Lab Bench Power Supply Conversion
Took me a full 10 minutes to make mine...

 

[handb94]

I have to bring my multimeter home from work and see what kind of power is coming out of it. I don't think I will need to pump running at full capacity anyways. I won't need that much volume of water.

I understand what you are saying. I will watch it for a while and see what the heat is like for the fire safety.

 

[handb94]

So the charger out of the wall is putting out 5.16 volts and .06 amps. Not a whole lot. Let's see how it runs the pump..... Works great in the test cup. Full scale test next..

 

[corrado33]

I'm not an electronics expert (more of a hobbyist) but it doesn't matter if your pump doesn't need to be fully powered. The point is it'll try to draw all of the amps that it wants. If your power source can't handle it, then that's a problem. If you want to see how many amps the pump draws, hook it up to a car battery. Since you have the pump, and the wires coming from it, it's pretty easy to take it out to your car really quick. Then wire it as you would normally to the car battery. Then unplug the positive wire, and put the black lead from the multimeter on the pump positive wire. Then put the read lead from the multimeter on the positive side of the battery. It should give you amps.

 

[cabezon]

I have mine running on a siphon from DT to sump.

 

[handb94]

I don't have a sump... Well I put it in a 10 gallon tank and let it run. It filled the canister and started pumping through, then I noticed it leaking at the connections on the canister where the tube goes it so I shut it off. I resealed it and I plugged it back in and nothing... Not sure yet. Don't have my meter with me so I don't know where power is running.

I think I might just buy a very small pump. I was just screwing around with this pump because I was bored. Oh well. I will update this if I do something different.