N/P reducing pellets (solid vodka dosing)

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I think the magroves may suffer as they rely on nitrogen and phosphorous as well as photosynthesis and the the new bacteria may out compete them for it..
 
Good to know thanks. I have 13 of them and they are growing well. Maybe I could use a smaller amount of pellets. The pellets just have to move around enough to rub against each other right? Is there such a thing of not having enough pellets to get some benefit from them?
Thanks
Tom
 
Quantity does matter...

Quantity does matter...

Is there such a thing of not having enough pellets to get some benefit from them?

I would say... absolutely!!! I watched my trates climb up, while I put off replacing the consumed volume of pellets. IME you have to match the volume of pellets with a given nutrient load (or surplus nutrient load if combined with other strategies) in order to gain maximum results. This is consistent with other forms of carbon (vodka) dosing as well.

HTH,

Sheldon
 
Any denitrifying bacteria fed by the pellets would be helpful in reducing NO3 . So even small amounts of pellets can help maintain or reduce NO3,imo. It might not be enough to match nitrogen going into the tank though ..
 
A Question for the Microbio & Chemistry Commentators

A Question for the Microbio & Chemistry Commentators

Hey Randy; Tom; Bertoni; and anyone else with any such science/filtration expertise...

This question stems from an observation drawn from a system in which I employ vodka/EtOH form carbon dosing. I've been looking after this particular reef for about 2.5 years; and have been dosing vodka for about 1.5 years (small break in between). I've just made a connection between the strange appearance of the employed calcium reactor, and the aforementioned carbon dosing strategy.

The CaCO3 reactor employed is a fairly large dual chamber reactor consisting of two [6" dia] x [36" tall] media chambers; the first of which is recirculating; while the second serves as a pass-thru buffering chamber which has in the past raised the effluent pH back up toward the 7.4 - 7.8 mark.

Prior to the carbon dosing regiment, I was able to pump about 1.5 bubbles per second of CO2 through the reactor to maintain an exit (post 2nd chamber) pH of 7.4. I don't have my log sheets in front of me at the moment but IIRC, Ca was 400 to 440ppm; and dKH was approx. 9-10 back in those pre-vodka days. In addition, the CaCO3 reactor was able to dissolve all of the fed-in CO2, i.e. no gas pocket sitting at the top of the first reactor chamber (which I should mention is downward water-flow).

Now this is where the serendipity begins... I've noticed for the past several months to a year or so, that I had to reduce the CO2 bubble count to as low as 1 bubble per 4 seconds so that a gas pocket (of undissolved CO2) would not form at the top of the first reactor. Added to this is the observation that the ARM coarse, and coral rubble media has a tendency to melt (i.e. visibly dissolve to dust) in both reactors to the point that calcareous dust literally smears down the inner acrylic walls of both chambers like muddy water on a car's windshield. So in a nutshell, I found that the ARM media literally melted away; despite practically shutting off the external CO2 supply. I strongly believe this to be a direct result of the employed vodka dosing regiment; but more on that later.


Upon experiencing the initial media melt-down, I dismantled the first media chamber only (since in the past the second chamber didn't really dissolve at all in the prior 1.5 years); cleaned out all of the dust & media; and restarted the entire system. Within two weeks, the same symptoms repeated... gas forming at the top of first reactor despite extremely reduced CO2 feed, and media melting away like mud streaking down the sides of the reactor.

At this point I assume the CaCO3 reactor is in need of some extensive servicing, so I bought myself some replacement polyethylene lines; took everything apart; replaced all of the PE tubing (which were getting clogged with calc paste); and cleaned and replaced all of the media, including that in the second chamber, which for some reason was also dissolving to dust... This time I ran it for about 3 weeks in an effort to allow all of the gas trapped by reassembly to passively dissolve out of the reactor before turning back on the external CO2 feed....

..... and here is where I got the biggest clue/confirmation of my submitted theory that carbon dosing is directly related to this anomalous calcium reactor behaviour: By the time the last of this (reassembly) gas bubble had actually fully disappeared; the ARM media had already begun to dissolve....BEFORE the external CO2 feed had actually been turned on!!!!!

I suddenly began to reflect on all of those discussions on the speculated effects and dynamics of this carbon dosing system we are learning so much about, and in particular, on its effect on O2 & pH. This is what I think is happening:
  • Carbon Dosing facilitates an abundance of C, N, P and O consuming; and CO2 producing bacteria;
  • Bacteria populated aquarium water very slowly makes its way through CaCO3 reactor in a manner suited to the proper operation of a conventional calcium reactor;
  • Said bacteria, eventually replaces all traces of O2 with CO2, thereby creating the acidic environment needed to dissolve calcareous media without the addition of external CO2;
  • Because bacteria is actually consuming O2; as opposed to the conventional CaCO3 reactor's formerly sterile operation, the subject effluent is enriched with dissolved Ca (calcium), but not so much CO3 (carbonate) *** see further observations below***.

Despite noticing the media dissolving even before resuming my external CO2 feed, I still offered a significantly reduced CO2 supply to the effect of 1 bubble per 4 seconds or so. The ARM media continues to dissolve like crazy, especially in the first chamber which is recirculating, but also in the second chamber which is just a pass-thru. I do have a small gas pocket trapped at the top of the first chamber, even with such a normally insignificant CO2 bubble count.

Before reinstating the CaCO3 reactor into the system, I was dosing Calcium Hydroxide, and Alkalinity to maintain Ca at 420; dKH at 7 - 8; and pH at 8.1 - 8.2. Since reinstatement, I decided to discontinue these liquid supplements to see what happens. Calcium rose up from 400 to 440ppm over the course of 2 - 3 weeks, and dKH dropped to 5.5 - 6 over the same amount of time. As the dKH is now lower, so too is my pH which hovers around 7.9 - 8.1 depending on whether the two macro algae refugiums are lit (huge bio-tower runs 24/7).

One last observation for consideration is that the pH of effluent coming off the CaCO3 reactor only seems to be affected (i.e. different from the system general) by the amount of CO2 fed in by the external feed (keep in mind that I have not been able to measure the pH isolated to the first chamber, but only that exiting the last stage of the full calc reactor system). For instance, when I was able to pump 1.5 bubbles per second (bps) into the reactor system prior to vodka dosing, the pH of the effluent running into my system sump (via the bio-tower) was as low as 7.4, and I presume it was probably as low as 6.5 within the primary recirculating chamber (and the media was not melting even 1/4 as fast as it is now); however, while running an established carbon dosed system, I'm finding that due to the insistent gas pocket that appears at the top of the primary reactor despite having a drastically reduced external CO2 feed (0.25bps), the net result of not being able to feed in a normal amount of CO2 is effluent pH (exiting to the sump) being almost the same as the pH entering the calc reactor system... i.e. if my overall reef pH is 8.1, the calc reactor effluent measures at 8.0-8.05... yet the media continues to melt away at an extremely fast rate....


My question(s)

  1. Does my above deduction make sense re: bacteria O2 consumption; CO2 production; and effect on CO3?
  2. How exactly does a Calcium reactor produce CO3: does fed-in CO2 associate with O2 to produce CO3 thereby raising system carbonate hardness?
  3. If the answer to the first question above is affirmative; then what process allows bacterial activity to acidify the environment within the calcium reactor, while not registering any noticeable pH drop in the effluent from the second chamber... could this chamber (of aragonite) be actually buffering pH back up to overall system levels even though its media is also melting away albeit not as aggressively as the first chamber's media?
  4. What other possibilities could explain the above described phenomenon that have not been considered or described...???

Sorry about the long winded post... hopefully this plays a part in helping the greater community refine our understanding of carbon based bacterial filtration systems. Thanks in advance for your replies.

Always curious,

Sheldon
 
Well, here's my update.

My nitrates have been at 0 (Elos) for the last 3+ weeks now but my phos got as low as 0.09 (Hanna Checker) and has been on the rise. It has gone from 0.09 to 0.11, to 0.14. I started adding nitrogen (Brightwell) because I thought I was nitrate limited and I have seen my phos go from 0.14 to 0.19 to 0.44. All the while my nitrates remain at 0. Cyano and gha are starting to take over and my bryopsis has almost returned to it's starting point. I'm debating about dumping the remainder of the nitrogen in and see what happens or just stop supplementing with nitrogen, do a massive scrubbing and water change and add GFO once I get a some and a reactor.
 
I"ve never tried any of the nitrogen dosing products, and probably wouldn't venture down that route personally. I would focus on managing your pH at an upper level of the range and steer away from dosing anything until the blooms have passed. I too am having a bit of difficulty reaching trace levels of phosphates, but I think my issue has more to do with gratuitous feeding of frozen foods to the system in question. I've decided to give the tank a frozen food break and see if there is any effect on PO4, all other things staying the same. Following that, my plan is to start using lanthanum chloride, if only I can get around to properly setting up the mechanical filtration component of it...

FWIW, the only time I've ever experienced a problem with bryopsis was when I believe my calcium reactor was dumping surplus CO2 back into my system (or perhaps even PO4).. whatever it was, I noticed the bryopsis outbreak disappeared once the Calc reactor was taken offline for a couple of weeks. In any event you should take a note of all your parameters, especially pH as I think that is a dynamic directly related to the use of carbon based bacterial filtration systems, and the additional CO2 is a great facilitator of all types of algae.

Regards,

Sheldon
 
Thanks Sheldon,

I think I'll just stop dosing because I'm not seeing any good results from it and just start doing several big water changes. If I still have phos problems then I'll add some GFO and go from there. A friend told me the phos may be leaching from my LR and that may be the source. I haven't fed commercial frozen food in quit a while, I made my own home made mush and have been feed that instead. My pH has been hanging out around 8.2 and really doesn't change that much and my calcium is from BRS. I don't have a Ca reactor yet but I want one. I've been reading that Kent Tech M at about the 1850 level will kill off the bryopsis so I think I'll give that a try too. When I first started the biopellets, the bryopsis did diminish but it's come back. Haven't figured out why yet.
 
Good luck!

Just for argument sake, test the PO4 of your frozen food recipe (in distilled water). Also be aware that if you do lots of water-changes, and your RO/DI unit is not working optimally you could end up with diatom algae as well, so just make sure your filters are up-to-date. On the magnesium note, I heard 1600 was the target for controlling algae?

Sheldon
 
Read your calcium reactor-related post with interest Sheldon and am looking forward to hearing more about this. I think the media consumption has picked up pace in my tank but not as much as what you've experienced with that dual chamber reactor. I've got a Korallin 1502 that is set at roughly 20 bubbles per minute and about 60 drips per minute. At that rate the media needed to be changed about every 5 months. Now that I've been using bio-pellets it looks like the media is dissolving faster definitely and a very rough estimate is roughly 25-50% faster.
Background- 150g tank. I started 4.5 months ago with bio-pellets in a Reef Octopus 150 reactor. Phosphates came down to .03-ish and nitrates to almost undetectable, corals (mixed lps and sps) growing like crazy and beautifully colored. Oh yeah- still running GFO. There's still a teensy bit of hair algae on one rock, and red fuzzy, velvetty (not cyano) algae is on most rocks. Blennies, tang and rabbitfish graze on the red stuff and I think it's some kind of macro but really have no idea (?).
Here's a very short video shot of the tank.
 
Read your calcium reactor-related post with interest Sheldon and am looking forward to hearing more about this. I think the media consumption has picked up pace in my tank but not as much as what you've experienced with that dual chamber reactor. I've got a Korallin 1502 that is set at roughly 20 bubbles per minute and about 60 drips per minute. At that rate the media needed to be changed about every 5 months. Now that I've been using bio-pellets it looks like the media is dissolving faster definitely and a very rough estimate is roughly 25-50% faster.
Background- 150g tank. I started 4.5 months ago with bio-pellets in a Reef Octopus 150 reactor. Phosphates came down to .03-ish and nitrates to almost undetectable, corals (mixed lps and sps) growing like crazy and beautifully colored. Oh yeah- still running GFO. There's still a teensy bit of hair algae on one rock, and red fuzzy, velvetty (not cyano) algae is on most rocks. Blennies, tang and rabbitfish graze on the red stuff and I think it's some kind of macro but really have no idea (?).
Here's a very short video shot of the tank.

Thanks for your response Greg... It's good to know that my observations are not in isolation. I really think it has to do with the O2/CO2 dynamic introduced into the equation as a result of the bacteria produced by any form of carbon dosing (both liquid and solid). In addition to C:N:P, these bacteria just like any other type of fauna/micro-fauna, are using O2 and respirating CO2, which in turn creates an acidic environment. It just so happens that the reduced flow rate needed for the function of our calcium reactors, happens to make good use of the bacteria's negative effect on pH to help dissolve our calcarious media.... I'm hoping that one of the bio-chemistry experts can chime in to add a little more understanding to the processes taking place.:crazy1:

I'll post a pic or few of the reactor media melt I described in the previous post, when I get a chance to sinc my blackberry with me home computer... actually at work right now and will have to follow up sometime tomorrow with the photos.

Cheers,

Sheldon
 
I did some aragonite sand i vacumed out of my display and putted into my pellets reactor.
The flow reduced due to the heavier sand particles , the folowing 2 weeks i had elevated alkinity numbers .
As i always dose 24/7 alkinity in thge same concentration , i has to be either that my corals didn uptake alkinity then (i do not believe) or that the sand has dissolved due to an acidic enviroment , into Ca and alkinity.

greetingzz tntneon :)
 
Good luck!

Just for argument sake, test the PO4 of your frozen food recipe (in distilled water). Also be aware that if you do lots of water-changes, and your RO/DI unit is not working optimally you could end up with diatom algae as well, so just make sure your filters are up-to-date. On the magnesium note, I heard 1600 was the target for controlling algae?

Sheldon

Hi Sheldon,

Thanks. The RO/DI system checks out but I didn't think of checking the home made mush. I figured that because I didn't add any additives it would be phos free. I'll check just to make sure. :)
 
Gregr,

Nice tank and nice video. :thumbsup: How fast do you have the pellets tumbling in your reactor? I'm not sure if mine are moving too fast or too slow. Thanks.
 
Thanks :)
A fairly slow tumble- there are areas where there is only a tiny bit of movement but every pellet does see flow- no completely dead areas and no fast tumbling. At that rate (I can do a quick video if you want) the media gets consumed pretty quick. Two months and I had to top it off.
 
bio pellets nuked my tank!

bio pellets nuked my tank!

I don't know if there are any horror stories posted from useing bio pellets and I have'nt read all this thread about them. I want to share my story in the hope that this will not happen to your tank! and possibly learn why this happened to mine! I have a 180g with 35g frag tank and 100g rubbermaid sump it has been running for 2 years, I had many sps colonies that were doing well. I picked up a calcuim reactor filled with media about 4 months ago and shortly after that I developed red slime, My phosphates would test .5 and my no3 was 15ppm, I continously ran gfo. I do a 30-40g water change every 2 weeks. I could not get rid of this slime, my lfs recomended dosing mb7 so I did that for 3 wks, 8 caps a day, still had it! So I read about the pellets and that you need a huge skimmer and I have a SWC 300 skimmer and to use less than recomended pellets (800ml) for the capacity of my system so I started with 300ml in a phosban 550 reactor with a mag 5 pump. They ran for 3 wks with no change so i added another 200ml for a total of 500ml after a total of 27 days I came home monday 6/27 to a cloudy tank and all the sps faded and clams, p's & z's, lps all closed. I immediately disconnected the reactor and did a water change, My lfs recomended I feed the fish more because the pellets brought the nutrients down too low, so I did that for a few days as things continued on a downhill spiral! I did'nt even think about having an ammonia problem until 4 days had passed and things were still getting worse! I have over 200# of live rock and 75# of sand in the system. I tested it on thurs .25, I have done 4 40gwc and today i'm at .1. for the last few days I have been clearing out all the dead! Talk about stink! my wife is freaking out about the smell and the tank and sump is in our basement! I'm adding mb7 in the hopes of rebuilding my bio filter. The fish look and act normal no problem with them yet and some things are beginning to open up and look a little better after all the water changes. I have finally rid my tank of the red slime! and all my sps colonies and 2 clams so far!
 
Sorry to hear about that. My 210 cracked about 6 months ago so I'm still rebuilding and I'm just about ready to hook up a 550 with biopellets. New tanks running good now hope it doesn't get screwed up like that.
Tom
 
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