batch denitrifier?

[stephenlchristopher]

ok people, I'm new to this and may be thinking I've invented a fabulous square wheel here, but it seems the big gripe with coil denitrifiers is getting the water to flow yet drip slowly enough that it isn't spitting nitrites back into the tank

so say a fool (me) was to build an ample set of tanks (4 connected 55gal drums) lidded, filled with bioballs or some such, and fed from the aquarium by a powerhead on a timer that ran x-minutes a day, so that the effect would be an x-percent water change every day.....so essentially, the tank would be getting water that had been sitting in the dark for a week or so....plenty of time for the fabled anaerobes to do their magic

and the water could pass through some dolomite and some carbon on the way in....oh and maybe some trickly deal to aerate as well...

am I missing something in my pop science here??

I'd build it and tell you now what happens, but I haven't even bought the house yet....maybe someone can set me straight ahead of time...

[Geoff]

Welcome to TRT!!!



denitrators walk a fine line. you want to flow slow enough to not get nitrates out the other end but not so slow that you get sulpher water out it either. sorry, i will need to go back through my denitrator threads to give you the proper terminology.

the problem is that the water can turn toxic if moved to slowly through a denitrator.

your idea would be dead on if this were not the case. there may be a length of time that you could put the tanks on a timer like you say and it will work, but i think that it will prolly be on the order of a couple of hours than a week.

G~

[stephenlchristopher]

hmmm...so, timing is really the issue...I'm not using any sulphur...and hopefully the carbon would bond to any errant 'toxins' lurking in the output until I get the thing testing clean

well, I have to move in the early spring, so I'll repost to let everyone know if I'm working water cycles rather than water changes...the tank I'm planning to build is 16' x 3' x 2', so water changes might wipe me out

of course, I'll do my beta version on my fw tank first....stay tuned...

[stephenlchristopher]

beta denitrator has been running for a year and a half and wiping out all nitrates handily.
one 55 gal drum filled with glass wool, run 1/2 hour per day by a power head on a timer
fish are happy, I guess. I haven't done a water change in a year and a half...I almost forget what it's like to carry a bucket of water...

[stephenlchristopher]

oh, that's for 3 tanks, total 230 gallons (not including 55 gal drum)

[jenglish]

Are these FO tanks or reefs? I've seen some algal filtered systems go years w/o a w/c but they had somewhat slower stoney growth due to limiting factors of minerals. I just wondered if you would see the same? SOunds like a cool project either way! What did you end up using for inside the drums? bio-balls? I would think sand would be cheaper. Just curious

[OneDummHikk]

Originally Posted by stephenlchristopher

of course, I'll do my beta version on my fw tank first....stay tuned...

Originally Posted by stephenlchristopher

beta denitrator has been running for a year and a half and wiping out all nitrates handily.

Are those one in the same where the beta denitrator is being run on a FW tank?

As for making a coil dentritator more efficient and be able to handle more flow through it, dosing it will accomplish that as well. Vodka, sugar, etc.. The dosing increases the metabolism of the bacteria and gets them to eat faster, thereby reducing nitrates faster and letting you speed the water flow up.

The concept itself is intriguing but if its being tested on a FW tank, the water change regimen is different. I ran my 55G overly stocked FW tank for almost two years before I moved it and the only water I ever put in it was top off from evaporation. Not a single waterchange ever. And when it was "overly stocked", I mean in the range of 150 or so 2" swordtails, a goldfish (he was my birth control to an extent), plecostomus (2, in excess of 8" each), catfishes (about 20 total), 4 different types of FW "sharks" and more. The fish almost fought over swimming space it was so crowded.

[stephenlchristopher]

lol...wow after two years that must've been a lot of nitrates. mine measure zero. I have two big oscars, a few mollies, a big pleco, a bunch of minnows and a handful of tetras...that's a fair amount of waste for my rig to deal with...in addition to constant growth and death of algae I feed the denitrator two tablespoons of sugar per week.

I don't have the money to do salt water yet, but it's coming...

[OneDummHikk]

I never tested that tank for anything. Not even nitrates. Only problems I ever had was after I transferred it to a 75 and then into a 90 where I started trying to control everything. I finally put it back into the 55 (after losing about 70% of what was in the tank) and leaving it alone. 9 months later I gave the fish away with a 30G tank that I didn't want to move again. Although for the last year or so, it was planted. Never did get it replanted when I moved it back into the 55 though.

[Jadinop]

Big differences in a filter being able to keep freshwater fish alive versus a reef tank. After seeing this story it amazes me how people still manage to kill their freshwater fish.

http://www.ananova.com/news/story/sm_2855526.html

[Jnicho]

Originally Posted by Jadinop

Big differences in a filter being able to keep freshwater fish alive versus a reef tank. After seeing this story it amazes me how people still manage to kill their freshwater fish.

http://www.ananova.com/news/story/sm_2855526.html

Wow...talk about amonia spikes!

I agree, while the concept is really cool, implementing this on saltwater it would likely not behave the same way.

[stephenlchristopher]

lol don't get insulted guys....all I'm saying is the nitrates are gone...not sayin' I even can BEGIN to understand the supercool mysterious and esoteric world of salt water!

(even though the nitrate cycle is exactly the same)

but a guy can dream...

[Jadinop]

Basically what you have setup is not a fuctioning as a denitrator. For a denitrator to function properly, you have to have an anaerobic or oxygen free area that stays constantly oxygen free. That is the reasoning behind using the long tubing. Oxygen is consumed by aerobic bacteria in the first part of the tube. Anaerobic bacteria will inhabit the last part of the tubing and the final bioball chamber (if there is one). This prevents oxygen from making it to the anaerobic bacteria because if it does the bacteria will die.

In your setup, you are flushing the system with oxygen rich water on a daily basis. Since it normally takes days (if not weeks) for the anaerobic bacteria to develop it is safe to say that your system would house very little denitrifying bacteria. Once the pump shuts off and the aerobic bacteria consume all of the oxygen from the new water, they most likely will die too before the next pump cycle due to lack of oxygen. There is a good chance that your pump cycling is actually wiping out any bacterial filtration before it can fully develop and the system is simply funtioning as a mechanical filter with the glass wool.

Yes the nitrate cycle is the same whether it fresh or salt but so are the rules of biological filtration. Aerobic and anaerobic bacteria cannot survive side by side.

[OneDummHikk]

Originally Posted by Jadinop

After seeing this story it amazes me how people still manage to kill their freshwater fish.

http://www.ananova.com/news/story/sm_2855526.html

That is freaky. Really freaky. Just when I thought I had come up with some of the craziest hair brained ideas I see that and it freaks me out. Man, I am gonna be thinking about that for a few days. Yeesh.

[Jnicho]

Originally Posted by OneDummHikk

That is freaky. Really freaky. Just when I thought I had come up with some of the craziest hair brained ideas I see that and it freaks me out. Man, I am gonna be thinking about that for a few days. Yeesh.

Irrelevant of what you've built...you've caught Randy dang near speechless...that in of itself is no small feat!!!!