Nitrate Filter

[slicksta]

Well I finally got around to my next experiment......
Theory: to create an oxygen free environment so anaerobic bacteria can flourish and consume nitrate. By allowing water to flow slowly through the long tube aerobic bacteria consume all the oxygen...

This isn't to hard to build....but does it work? From what I understand it can take up to 8 weeks to cycle.
This unit is be being fed by a mag pump that I have sitting in my sump. (This pump is also being used to pull water thru a carbon sleeve and circulate water around my main pump to cool it and heat my water)

Water is taken from the sump and pumped to the top of the coil where it circulates down and around to the bottom. Then it enters the bottom of the PVC filled with bioballs and exits the top and back to the sump.

The drip emitter allows me to set the flow at about 60 drops per second......

http://gallery.pethobbyist.com/data/17593Nitrate.jpg

[jaydoc]

Interesting idea. Do you think it will circulate fast enough to keep up with nitrate production? Won't you still need the same amount of water changes to remove organics?

[slicksta]

Carry
the ones I have read about use just a coil for the process, and they claim to reduce nitrates from 20ppm to 5ppm at that flow rate. I am hoping to increase that by the use of the bioball chamber.
Currently doing 30-40% weekly water changes at which point my nitrate peaks at 20. So with the addition of this unit I am shooting for bi-monthly.
Nothing will eliminate WC but if I can keep 'trates close to 0, I think it would be beneficial. This would be great for those times I am on vacation.

besides it is still to cold out here in the nyc area and this is a good way to aid with cabin fever..... ;D

[rdeis]

And any disruption may regquire the cycle to restart, and serious failures (most notable too hugh a flow rate) can emit hydrogen sulfide (I think) into your tank?

I looked into this, but given the fact that nitrate is only one of several pollutants that drive water changes, it seems too much risk for too little benefit. Looks like the reef guys get more use out of these coils, but I don't know why.

I would think that a floating band of water sprite, dangling philodendron roots, or similar would do a lot more for water quality with less risk.

Plants supply O2 and eat more pollutants than just nitrate-- and using emmersed or floating plants can prevent the needs for lighting CO2, and ferts that conventional planted tanks tend to have.

[rdeis]

That said...



Water is taken from the sump and pumped to the top of the coil where it circulates down and around to the bottom. Then it enters the bottom of the PVC filled with bioballs and exits the top and back to the sump.


Your theory is to improve on the denitrification coils by expanding the 2nd half of the coil (which is anerobic) into the bioball to get more of the N2 producing bacteria? Interesting.

Two things to consider:
1> As I understand it, the entire point of using the very long, thin coil of tube is to ensure the anerobic conditions set up correctly by exposing a very small amount of water to a particular culture space in the bacteria, and moving that small amount of water along to the next space without letting it mix with any other water. Your open bioball space would allow (cause?) a lot of mixture in the flow in that part of the system. I'd be worried about that disrupting the anerobic setup.

Then again, if it's after a long enough coil it might be fine? WHich brings the second thing:
2> Are there intermediate products in the breakdown of the NO3? I don't know whether, for example, the hydrogen sulfide is simply a catalyst/byproduct in the whole process, or an intermediate thing that shows up in the first part of the filter and must be consumed for the second part to work. (Like nitrites in the normal bio filter)

If it's the latter, then the length of the coil determines how things work (becasue that's where the HS is made), and the bioballs don't add benefit, because you won't grow any more bacteria than there is HS to consume.

If it's the former, never mind...

Oh, one other thing- most of the commercial ones I've seen run the flow in an upward spiral to make sure the gaseous nitrogen can escape. I get the impression that they are worried about bubbles trying to run upward against the downward flow and causing problems? Maybe the get redisolved or something, dunno. Yours is showing a downward flow.

[ronrca]

Im curious as to what happens to the nitrite level then! The denitrifrication process is basicly the nitrogen cycle, backwards. ???

[rdeis]

I'm not sure what you mean.. De-nitrification coils must be anerobic to work, and I'm fairly certain that there's no nitrite involved in the reactions?

It takes in nitrate and puts out N2 and 02, and since its aerated as it trickles back to the sump excess gasses are released to atmosphere. A fantastic effect once it's working and stable.

[ronrca]

there's no nitrite involved in the reactions
Well, like I mentioned, the denitrifrication process is basicly the nitrogen cycle, backwards. The nitrogen cycle beginning with ammonia, then nitrite and lastly nitrate. Therefore, denitrification or de-nitrogen will start with nitrate then nitrite and lastly ammonia. Each 'stage' of the denitrification process releases or gives off a 02 atom thus providing the bacteria their oxygen.

In the nitrogen cycle, bacteria add a 02 atom to nitrite to make nitrate.
N03 (nitrate) = N02(nitrite) + 02 (oxygen)

However, in the denitrification process which is 02 free (or lack of 02), the bacteria will use the nitrate as a source of 02 resulting in N02 (nitrite) and so on until nitrogen gas is produced.

http://www.ntlabs.co.uk/Lower_nitratesP2.htm


De-nitrification coils must be anerobic to work Anerobic meaning presence of 02 in the water. Anaerobic meaning lacking 02. Denitrification only works with lack of 02. ;)

[slicksta]

As stated in the article
"These bacteria are aerobic - they need oxygen. However if these bacteria, and many environmental bacteria like them, should find themselves in an anaerobic environment (where the oxygen concentration is zero), they use the nitrate and nitrite as a source of oxygen, breaking NO3 and NO2 down into oxygen and free nitrogen as shown in the diagram"


This is what I am shooting for....
I am not betting the house on it....just curious of the results I can achieve.

[rdeis]

So where does the HS come in?

http://archimedes.galilei.com/raiar/denitrif.html

[slicksta]

Not sure of your question....what is HS

NITRAGON FILTER
Base is 5X5’. unit is 13-1/4” x 2-3/4”
This denitrator is a hollow cylinder with a long coiling flexible hose inside. Water enters the top of the reactor via a feeder line operating under gravity or suction & runs down the winding coil. It is discharged at the bottom of the coil, fills the cylinder. & escapes at the top of the unit. Water moves between 50-60 drops per minute & it may be 3-4 weeks before nitrate levels are reduced. No need to feed this unit, Good for tanks up to 60 gallons.
Hang the small reactor input j tube on the edge of the tank. Place the reactor next to the sump or elevated slightly above the sump & place the return on the tank edge so that the water can drip into the sump. To operate, apply suction at the output hose with the control valve fully open, water will fill reactor & start following into the sump. Close down control valve to 40-50 drops per minute.
NON SUMP OPERATION: this requires the use of the input tee adaptor inline. To operate, open the control valve & apply suction at the outlet hose. Reconnect airline hose to reactor. Turn on the filter/pump. Water will siphon into the main line. When water flow in airline tube is steady close the control valve. Remove reactor ‘1 tube from tank & place in a 1 oz bottle full of tank water. Time how long it takes for the bottle to be emptied (1oz=600 drop) SPECIAL NOTE: Once the nitrate levels have dropped to 5ppm, the regulator valve must be full opened to feed the bacteria on water turnovers, otherwise there is a risk of bacterial die off, which can result in the production of hydrogen sulfide gas.
http://www.thatpetplace.com/images/p600b.jpg

The differences are...I wrapped my coil around the outside, and the chamber is empty and I added bioballs..
This unit also starts at the top and water flows down as mine does.

[ronrca]

HS = Hydrogen Sulfide

I understand the filter and the concept which is neat but will the ammonia levels not harm the fish eventually or are you counting on the nitrogen cycle to take care of ammonia/nitrite and the denitrifcation to handle nitrate which basicly means 2 cycles working together to produce nitrogen with no nitrate? ;)

[slicksta]

That is what I am shooting for..
I plan on testing the output of the reactor for nitrate and ammonia. From what I have read you should end up with N gas not ammonia. I guess if there was ammonia I could run the output back over the trickle filter instead of going into the sump.....but at that point it might make the whole thing useless. Tonight will be the end of the first week, so I will take my first readings Sunday morning.

[mattrox]

My under standing of the reaction is that NO3 - ions are turned into N2 and O2. This would mean that ammonia is out of the loop. The over all chemical reaction would be something like:

2 NO3- ----> N2 + 3O2 I don't know how the negative charge is balanced on the left of the equation..... I'll go do some research


Ok back. It seems that N2O is also produced.... Nitrous Oxide.... Don't let it off gas in a confined space..... you might find the discus much more amusing. :p (joke)

[mattrox]

I found a reaction.......

106(CH2O)16(NH3) + H3PO4 + 94HNO3 ----> 106CO2 + H3PO4 + 177H2O + 55.2N2

It seems this reation needs ammonia, and phosphate as well as nitrate.

http://www.ozestuaries.org/indicators/Def_denitrification.html

[mattrox]

I found a different reaction at this page.

http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Environmental/DENITE/schematic.htm

This one looks a bit concerning because it suggests that hydroxide ions are produced. That would make your pH alkaline... or atleast react with any acids... ie carbonic acid ...... Don't know if that will upset the apple cart in a carbon dioxide fed system???

[slicksta]

OK......as I expected
Lets test nitrates in the aquarium first.....somewhere between 10-20ppm....seemed a little lower than usual....but I hadn't done a test for some time.
So next I did a nitrate test from the reactor output......again somewhere between 10-20ppm.. Side by side the two tests were identical. So for the first week the reactor is not having any affect. From what I have read, I should not expect to see any results in the first month.....but in the interest of science, I will do them weekly.

[mattrox]

This is a very interesting topic. I can't wait to see the results.

[slicksta]

Week 2
To my surprise, results have already started. It is hard to tell from the photo, but there is a 10ppm difference between the input and output of the reactor. It may have started to cycle quickly because the bioballs I used were right out of my wet/dry. The existing bacteria must have depleted the O2 in the main chamber.
In daylight the test is much easier to read than from the photo.
#1 Output from reactor = 10ppm
#2 Aquarium = 20ppm

[M0oN]

Alright Slicksta, that's excellent, you might have to start selling these units to simply members ;)

[ronrca]

:thumbsup:

[slicksta]

there was some discussion that the reactor may possibly create ammonia in it's operation instead of nitrogen gas....since the reactor started reducing nitrate I figured I should check. So far so good....0 ammonia registering on a test from the output.....

[slicksta]

Well week three is over and things seem to be working well. Again it is hard to tell from a photo so...

#1 Reactor output = 0ppm
#2 Aquarium = 20ppm

So my little anaerobic friends are hard at work....but I am still reading 20ppm in the aquarium....so time for a WC... ;D
At this point I have increased the drip rate from 55-60 drops/minute to 95-100/minute. As I have read this is the tricky part. I may need to change my drip emitter if I need a more variable drip rate. The slightest movement of the valve has a large effect on the flow rate. The one I am using has a value of 0 - 2gph....basically it is a small ball valve....I may need to find a tiny gate valve if need be.

[Steve_Warner]

Hi all,
Slick, lookin good on that experiment. It's very interesting that they are doing such an efficient job at NitrAte reduction. By the way just for an FYI for all, according to the book "Discus Health" written by Untergasser, the bacteria that are reducing NitrAte are AEROBIC bacteria, which are utilizing the Oxygen bound in a NitrAte ion as their respiratory Oxygen. It says there are no known ANaerobic bacteria yet discovered that can reduce NitrAte. The aerobic bac. reproduce from the Oxy contained in the NitrAte ion. Can you tell me if you have Calcium in your water and if you've noticed the pH remaining stable due to this process(I would bet it does)? If you have Calc in your water(Calcium Hydrogen Carbonate), then theoretically your pH should remain pretty rock-solid stable since you have a healthy functioning bio-cycle. Cool experiment and good job :thumbsup:


Steve

[Steve_Warner]

Hi all,
I have just been reading up on this subject more and it seems there are conflicting beliefs about what type of bac reduce NitrAte. On one site,

http://saltaquarium.about.com/cs/nitratecontrol/a/aa092702.htm

it is said that ANaerobic bacteria are reducing the NitrAte(in salt tanks-maybe it's diff in salt to fresh), but in Untergasser's book, it says that there are NO KNOWN bac yet discovered that can do this(Page 153, far right coulmn, middle of page up). So who is right? I have been thinking about it and if you run it logically through your brain, it would seem that Aerobic bac would be the answer from Slicks experiment. It has been up and running for about three weeks and he has MAJOR reduction going on in the coil! How could An. Bac(requiring anoxic conditions) grow that fast in that short of time (in an environment-tank-probably filled with available Oxygen) to make that level of impact on the NitrAtes. It would seem to me that his results would lead me more to the Aerobs than the Anaerobs. Thoughts?



Steve

[ronrca]

Yes Steve, I have also heard of both types! I have also read that anerobic bacteria can 'convert' to ANaerobic bacteria when there is a lack of 02! I almost think that it is in referance to the process occuring rather than a name of the strain of bacteria! ??? Just a thought!

[slicksta]

I believe the word Anaerobic in this instance is as described by Webster.

1. not needing oxygen: living or taking place in the absence of oxygen, especially not requiring oxygen for metabolism.

This is why you need the long coil....... To create the environment. It is not the name of the bacteria...it is the environment they live in.

[ronrca]

:thumbsup: Thats what I thought also! It does make more sense that bacteria can 'adapt' to their environment!

[slicksta]

Week Four......
Well I flocked up!!!

It seems I was a bit over confident last week when I doubled the flow rate. The little guys couldn't keep up and the nitrate reading out of the reactor was equal to that in the aquarium....20 ppm. This leaves me with a few scenarios...

1 The anaerobic bacteria do not multiply that quickly and need more time do so...... I will need to increase the flow gradually.

2 The length of tubing that I used is not long enough thus not allowing all the oxygen to be consumed at higher flow rates..... Increase the length of tubing.

3 The whole project is a nice idea, but impractical.....Turn it into a still.... ;D

I am hoping for #1 and have set the flow back down to 55 dpm. When I start to get a 0 ppm reading again I will try to increase the flow slowly...10-15 dpm weekly and see what results I get.

Have a Happy Easter....

[slicksta]

well I'm back on track....
Week 5

Nitrate levels out of the reactor are back down to 0.
I have made a more modest increase to 70 drops per minute from 55 dpm this time.
I will check this mid week to see what effect this 25% increase in flow has on nitrate levels out of the reactor.

If your in the NE.....I hope your enjoying this absolutely beautiful week-end we are having.

[Lauren]

im loving this thread, its quite interesting think i've learned more about nitrates than I'll ever need to know

on another note it was 80 today here in MAINE! WEEEEE
I had to open all the windows, and the basement door to heat up my room & get some fresh air. I swept the stairs to the basement and found 2 salamanders (I dont even live near a river/stream that I know of) I showed them to my family & put them outside under the porch after spraying the leaves with some extra water for them.
I only wish I had real windows in my room or fish room.

Lauren

[slicksta]

thanks Lauren...

WEEK 6
Things didn't run perfectly in that the flow dropped from the 70dpm to 60dpm sometime during the week without me making any adjustments. Good news is that the reactor is still putting out 0 nitrates. I definitely have to come up with a better device for adjusting flow....
anybody have any suggestions..... ???
Still no measurable drop in nitrates in the aquarium.
for the upcoming week I have set it to 80dpm...

[Chris McMahon]

80dpm. Using 20 drops/millilitre that's about 240ml per hour (~8 fluid ounces). I'd say that you lack the flow volume to have any measurable effect on your tank.

I'd guess you'd need to pass at least 2% of your tank volume per hour through the thing before you notice any change in the tank.

What's the volume of your tank?

[Smokey]

Below is an exert from Saltwater Aquariums

Nitrate isn't good for our systems, be they FO (fish-only) or reef. To accomplish nitrate reduction or eliminate the levels of nitrate that build-up in our closed saltwater systems you can buy a commercial denitrator that cost big bucks, is difficult to adjust, and requires feeding and monitoring to maintain proper operation.
However, another very low-tech solution to very common nitrate woes is a coil denitrator! Essentially nothing more than a cylinder with a coil of tubing and some bioballs, this device works and achieves the same denitrification results as the more complex and costly commercial units, but much easier and more naturally.

How a Coil Denitrator Works
A coil denitrator takes 5 to 6 weeks to cycle (yes, they cycle just like the tank). The quantity of product that is processed, (nitrate) is truly amazing, considering how once established there isn't anything more to do! So how does this happen? As oxygen rich water is pumped into (G) and enters the top of the unit (A) it is forced to spiral down through the layers of plastic coil tubing (E) until exiting within the center of the cylinder (C). As the water level increases within the body of the unit, the bioballs (F) become host to the millions of colonies of bacteria that commence multiplying. As the water reaches back up to the top, it exits through the other fitting (B), the one not internally connected that runs back to your sump or display tank. So? So, as the water slowly works it's way down the spiral, the O-2 is consumed by the AEROBIC (living only in the presence of oxygen) bacteria, the same ones that are in your filter and make all the life possible. Somewhere around 3/4th's of the way down however, the O-2 levels diminish within the spiral, having been consumed by the aerobic bacteria higher up the coil. (D=Base)

Now what? Well, now the ANAEROBIC (can live in the absence of atmospheric oxygen) bacteria begin to flourish, the very ones that feed on nitrate, not O-2! As the water continues its travels it encounters the main interior chamber of the cylinder. All those bioballs are just waiting to provide area for more anaerobic bacteria to consume all the nitrate that wasn't converted inside the bottom 1/4 of coil. This is the "bank" that will allow the coil denitrator to continuously process more and more nitrate as it is produced within the display tank. By the way, if you are using a wet-dry or trickle filter with ANY media, you have a nitrate "producing" filter! Yup, that's what they are designed to do, convert ammonia ultimately into nitrates! Nothing like adding more in so we can spend more money to get it out, huh?
END QUOTE.

Smokey

p.s. any tank which has substrate, and allowed to fall into an anaerobic state, is this where the process can begin.[?].

[Rick_May]

from what I'm reading (thanks Smokey) It appears that its just a question of length to deplete O2 and start removing Nitrate. So I'm pondering how long a hose I would need to do like a 50gph.....what do you think 200' 300'? I think it could be built using 1/4" plastic AC water supply link and its pretty cheap....

[Smokey]

Rick; and all other members reading this post:
First - thank you to Slicksta, for posting this incrediable knowledgable/intellectial post/ - experiment. Thank you Slick.
Second - my personal thanks to all who have posted the "question critic". Those members who have questioned the operation off such a device. To me this suggests an open - inquistiver mind. e.g. - " Why does it work, How does it work. and just how efficient does it work.
Third - this device does work. MPE
Fourth - Is it approiate for a Discus tank. In MPO/MPE: It is not as effiicienct as W/C's. {mpo]
Reason - the % of water changes necessary for the prolonged life of healthy discus overrides the efficienty of a denitratification unit. again MPE.
Fifth - please suppot any member who goes out [ on the preverbial LIMB and tries something new [ within practial proven parameters].
6th- we all have something to learn. Right ?
AND
finally - who should we learn from - Pioneers or those who have not ventured forward. again mpo.

From my personal time/expierences - re: pre - internet access - I had to beat the pavement to learn from the Masters. Purchase expensive books[ written by experterts]; and read, read, and reread these books.
NOW with the internet, at my finger tips, I can explore all the written words of wisdom. AND challendge these writings. [ if approiate!].
However - I have also learned to read [sometimes between the lines!] of the wonderness of such things that work - and others, which may not be so appropiate[!].

I may lean on one side of the of the barbed - wire - fence; However, I do listen to the fellow on the other side. After all he is my neighbour.

Simply Discus, is one these very informentive sites.
Members can write their personal expierences; success and/or not so successful.

Are there any failures,[?] - [actually - yes. ]
If, as I have, you as a member, have read postings of those who have expierenced personal loss's.
Some have deceided to "walk away"! > Others have deceide to take on the "KING".
My hat off to these members.

Smokey
Please suppot those who challendge the other side of the fence. How-else would we learn what works and what may not work, as well.[ ??].

p.s. - MPE/O:
if it is in the garbage bin - I do not purchase/try that item again.[ mind you it may take me a long time to realize this!! I'm a slow learner.}/{ or I may have just screwed up}.... OR .....{Read the instructions ... WHY??}.. lol... ahhhhhhhh.
Welcome to my world.

[slicksta]

thanks all for the interest.....
Chris Mc'
I wasn't expecting a lower reading in the aquarium just yet...I was just stating the info I am gathering. This is on a 155 gallon set-up, with the sump....maybe 160 G.
so you think I have to get it up to 3.2 gph....should be do-able..I hope my coil is long enough

John

[Chris McMahon]

so you think I have to get it up to 3.2 gph....should be do-able..I hope my coil is long enoughIt'd say that would be the bare minimum. Of course if your tank is generating nitrate faster than your getting rid of it...

Have you thought of adding a fluidised bed filter to the output of the hose?

[Louiceman]

Hi slicksta :)
Very interesting experiment
I got 2 system working about 7 days.
What's your nitrite level :idea2:
Lou

[slicksta]

Week 7
No new developments.
Output from the reactor still 0ppm
Aquarium levels still at 20 ppm before my weekly WC
Still haven't found a better device for adjusting flow, although this week all went well. A nurse friend of mine hooked me up with some I.V. drip set-ups, but the tubing is to small...I'm hoping soon I'll just be able to let it run wide open.
Have bumped the flow to 100dpm

Lou...what are you using to adjust flow?
have pics of your set-up....post'em

[Lance_Krueger]

I thought I remember reading about George Booth (the plant guy) using just a coiled up black hose (maybe a hundred feet) and dripping into the end of it, and just leaving it coiled up in the bottom of his sump (wet/dry). I think I remember him saying that he could get more production of nitrate reduction by lengthening the hose. Maybe your limiting factor, Slicksta, is your hose is too short. Just some thoughts.
Lance Krueger

[Louiceman]

Here my set up:)
It still need more time but another system i set up it working, waiting for ORP Meter from RandalB to monitor system.
LOU

[slicksta]

Slicksta, is your hose is too short.

Lance
HEY.... who told you...

It maybe...but from the DIY ones I have read about and the ones they sell...all hoses were under 75'.
..as of now it is to soon to tell....if I can't get the flow rate high enough to make a difference in the aquarium...then yes I will be adding more hose. At this point I do not want to disturb it so I will wait and see what the next few weeks will bring.

Lou....
your hose is definitely bigger than mine.....

[mikeos]

Has anyone tried increasing the flow untill you get maybe 5ppm nitrate from the denitrifier? If the outflow is at 0ppm then you are probably not using the full capacity of the filter. you can then adjust back untill you get 0 if you wanted to and be sure things are working at maximim efficiency.

[Louiceman]

;DSlicksta another setup i use is Aqua Medic 1000 built /w poor quarlity manual not clear no picture so any way i make it work, inside aqua medic fill by bioball and circulation pump i siphon tank water inside fill it up NO AIR then i shut valve from intake - outtake turn it on let pump circulate water in side.
day 1 to day 3 nothing happen
day 4 nitrate decrease from 40ppm. to 20 ppm. and nitrite increase to 5 ppm.
day 5 nitrate 10 ppm and nitrite still 5 ppm. cycle is REVERSED I'm in deep sh......
to be continue

[Louiceman]

:bounce2: :drummer: :bounce2:
day 5 cycle had reversed so that mean biological bacteria need more help, I give 2 tbs of STRESS ZYME to increase bacteria
day 6 BINGO nitrate 0, nitrite 0, I check it 5 TIMES!
Now I'm going to build 40 g. unit for 125 g. tank so no more water change for me.
see picture

[slicksta]

Lou
are these readings from the reactor or the aquarium.
what is your flow rate...
John

[Louiceman]

Reading from reactor.
day 6 i turn valve on inflow and outflow adjust flow rate 120 dpm.
day 7 nitrite 0 nitrate 5 ppm. adjust flow rate 60 dpm.
Unit too small for 125 g. tank
LOU

[AndyL]

Just curious - any updates slicksta and lou?

I built one to test out on one of my racks, 150' (whole roll is much cheaper than by the foot) of 3/8 tubing. Flow control is a ball valve (fine adjustments are difficult - but do-able). I'm currently seeing no measurable nitrogens coming out the effluent, though I'm having some issues with H2S - so I'm slowly increasing my flow rates. Not a big deal.

After discussing the project with a reefer who's very knowledgeable in denitrator coils, he figures once fully cycled, I should be able to hit almost 4gph with this setup due to the length and diameter of the tubing.

Andy

[Louiceman]

Sorry take so long :)
Here is my nitrate reducer 30 gal water tank
Out put 2- 4 gph last time i ckeck nitrate acouple days ago
5 ppm. tank and out put nitrate reducer it been like this for acouple
month :bounce: :drummer: :bounce2:

[Louiceman]

Here what is look like

[Louiceman]

Here

[Louiceman]

One more time

[Louiceman]

Another

[slicksta]

Long time no update. Sorry guys...
.....things got busy and my original set-up crashed. No ill effects, but the flow was cut for a few days and the reactor died. I did get it running again but could never get the flow rate up high enough to make a difference in the aquarium. Recently I have made the following changes.

1 Increased the tubing length to 300' total. I feel this was the reason I could not get the proper flow rate.
2. Added a second increased capacity reactor. I used smaller 1" bioballs and 2 cups of bio-max fine pore ceramic media. This should increase surface area for the bacteria dramatically. The set-up is running in series. My plan is to eventually move the original reactor to a 75 gallon tank with it's own 300' length of tubing. I started it this way as I figured it would help the new set-up cycle. I think it has worked out as I've seen an increased output in less than two weeks.
3. Finally found a large roller type valve (same type used in hospitals for I.V. drip)to adjust flow rate. This gives excellent adjustment and made cycling the reactor easier.

Currently I have the reactor running at 2.5 gallons/hour and there is a 0 nitrate reading at it's output. This has been running like this for a week now. I've still been doing my weekly water changes and my aquarium had a reading of 20ppm just before the WC.
I think I may see a reduced nitrate reading in the aquarium at the end of this week now that I have been able to reach a higher flow rate. We will see.......

John

[slicksta]

Well Monday is here....the day I typically do a 40 - 50% water-change on my 155g community aquarium.
I have to say....I'm very happy with the results of the experiment today. After one week of running at a higher flow rate (2.5gph)....I have a reading of 0ppm for nitrates in both the reactor output and aquarium..
This is what I was shooting for.
I see no change in the aquarium as far as fish behavior, eating habits or water clarity or odor.
I did notice a change in pH from just below 6 to just above 6. It' hard to get an exact reading as the only test I found that goes that low is a wide range test that reads in .5 increments. I actually think this may be an unforeseen bonus as I always thought my pH was a bit too low....but the fish were always happy....so what do I know.
I will do a water-change today of 15-25%. Just enough to vacuum the gravel.
1.. to see if I can maintain these readings for another week, and see how the fish react.
2.. I don't want to cut the food supply to the reactor by doing to large of a change.

If I continue to get these results with no change in fish behavior....I may cut my WC to bimonthly....this will be great...especially when I go on vacation.

I have to add...as I was trying to take a water sample for the test this morning...one of my golds kept nipping at the tube as a red marl sat with his mouth perched out of the water and was spitting a stream of water on my hand.
You have to love these fish....
Have a great labor day....
John

[Smokey]

Lou / John:
Thanks for the updates. I was wondering how things were going.

Has there been any change{s} in the pH, GH, KH, etc. numbers[?].

Keeps us updated as the experiments continue.

Smokey

[slicksta]

Ended up doing a 30% change last Monday...gave the glass a good wipe down so I let out a little more water in the process.
This weeks reading are:
0ppm - Reactor output
7-8ppm - Aquarium
pH 6.5
The aquarium was just below half the normal 20ppm that it usually is just before my weekly water change.
I am going to go a 2nd week without a water change to see what the results are. I will be monitoring nitrate levels and fish behavior closely during this time