At the top of my recirculation tank I built a 3" deep rectangular tray with two large holes on the bottom. Two coarse nylon bag filter set in these holes. Into the bags I add a handful of filter floss. All of my tank overflow is directed through the bag filters. As the bag filter begin to clog with waste, the water rises a couple of inches and over flows the tray into the recirculation tank.
My tank has periodic heavy recirculation and little waste ever collects on the bottom. The floss always has detrius and uneated food in it, so I always have nitrogen and phosphate available in the filter to limit the possiblity of the bacteria growth becoming N or P limited. If I am not using it in conjunction with Vodka dozing the bags and floss is replaced daily so it does not become a nitrate factory. It is a two minute job or 10 minutes in the morning with a cup of coffee and fish watching.
Before I go to bed, I only dose 1/2 ml of Vodka / 25 G of tank capacity but it is directly into the filter tray...not into the tank. I also dose an amino acid and dry phytoplankton mix with the Vodka, directly into the tank, to enrich the bacteria and replace excess nutrient depletion. Within two hours you will see the bags develop bacteria slime on the outside if you have excess phosphate and nitrates in the water column..
If my tank has excess nutrients, the floss inside the bag filter will clog and cause the water flowing into the tray to start over flowing within 6 to 8 hours. The outside of the bag looks like Santa's beard from the bacteria slime. When I am dosing Vodka I do not let the bags go more than 12 hours without being emptied, otherwise the bacteria slime starts breaking down and reentering the water column.
The over flow indicates to me the bag is loaded with a nitrogen and phosphate laden bacteria biomass. In the morning I toss the floss in the garbage....the most positive export I can think of. The floss is like picking up a hand full of snot or watery jello it is so filled with bacteria. My skimmer is working over time while I'm dosing Vodka.
If the tray doesn't over flow within 8 hours from the build up of biomass, I stop dosing Vodka for a week, and then start over again. The reduced bacteria growth indicates to me P and N are reduced enough. It maintains enough nutrients to keep softies and reduces them enough to keep SPS. The mandrin, tangs, etc; are all fat.
While I am dosing Vodka I don't feed the tank. Although bacteria build up in ther tank is reduced, if you look closely you can see that there is plenty of white bacteria film on all the surfaces and in the water column for the fish and coral to feed on. The fish love the white bacteria film and nibble on it all day.
Neither excess nitrates or phosphates, nor available coral food are an issue in my system. The tank is bare bottom. I can start and stop the system with out adverse effects. As I said, it works for me. I am not worried about my tank suddenly flipping from uncontrolled phosphate release, if for any reason pH or salinity changes.
I came up with the dosing rate based on several good articles on Vodka dosing from Europe. One was based on dosing for 18 months at about 1ml/100L average.
Initially I started using the ZEO process and I started to better understand what it was doing, and I then started I coming up with my own ideas in an attempt to improve or make easier. The ZEO process does a great job of making any user aware of the importance and dramatic affect from adding a few drops of anything. It emphases the importance of controlled feed and good observation. I believe the main reason for shaking the zeolite rock several times a day is as much for putting the bacteria into suspension, so that the skimmer can export N&P bacteria, as it is to feed the coral with enriched bacteria.
I replaced ZEO food, an acetic acid base product, with Vodka. I am considering blending some vinegar with my Vodka to get more diverse bacteria population.
When I used the ZEO process, I used zeolite rock in the filter bags and covered them with filter floss. I did not notice any negative results. What I did notice was the filter floss was a better home for bacteria biomass than the zeolite rock. I quickly discovered more bacteria was growing heavier on the floss than on the rock.
In the ZEO process the zeolite rock has an affinity for grabbing ammonia and I assume feeding the bacteria with it. I believe the Vodka acts directly on grabbing ammonia and is probably working as well on direct ammonia removal.
It was also visually apparent that tossing the bacteria laden floss, rather than shaking the zeolite rocks, was a more efficient method of exporting N&P laden bacteria.
Using the ZEO process also made me aware of the importance of feeding amino acids to keep the system from becoming depleted by the pulling out too much along with the N&P laden bacteria. I use Reef Crystal salt that has more trace elements and I do 25% water changes every two weeks to address trace element depletion.
I found 1/2 ml per 100L works well the way I was using it with floss in NPR. I cut the normal dose in half because it didn't require a higher dose to work. Dosing more just caused more bacteria to bloom inside the tank on the walls and rock. I want some bloom on the tank rock and wall to pull out the residual P, but not a lot. Using only 1/2 ml per 100L slows down the export process. Too fast a rate of change, good or bad, is what often causes havoc in a reef tank.....except for water changes It appears starting and stopping the process when dosed in this manner has no ill effects on the tank. Now that I have no signs of alages on my live rock, I only dose on the week end.
It may take a month or two before you see measureable change. What you will notice is any problem algaes (bryopsis, cyano, dino, bubble, hair, etcalgaes) slow down in growth and then turn white over weeks as phosphate is removed. The Tangs and fish that wouldn't eat bryopsis before will eat the white bacteria covered remains.
DO NOT even consider using NPR unless you have a great skimmer.
I am the same guy that started CPW ( controlled plenum wasting), which does work. I stopped using CPW when I realized that by improving on methods to physically export waste and nutrient laden bacteria just made more sense, plus it was easier to control. It is more efficient, and less apt to get unbalanced than trying to biologically treat waste inside the system.
Many of the negative comments about adding any external carbon source are correct and should be heeded. It is easy to over dose and is the primary reason failures have occurred. It is why I mentioned it is important to have a high degree of control and patience, like the methods used in apply the ZEO process.
It’s potential negative effects on other types of bacteria within a DSB are real. The potential for bacterial upset in a DSB can also be caused many other things, which will bring on the same problems you described alcohol causing, which is a large part of my reasoning for becoming a BB advocate.
My recommended Vodka dosing is much lower than most have prescribed in using alcohol in the past and much closer to how the ZEO process is applied. Simply allowing the bacteria to die, put the nutrients back into the system, is why I say to remove the bacteria laden floss after 8 hours. Not simply shaking it to break it loose and allow the skimmer to do all the work.
Most everyone acknowledges that phosphates, in some form, does slowy saturate DSB and even live rock (reason for cooking live rock) in all reef tanks. Using only conventional process only, and not also keeping up with phosphate removal, is also walking a tightrope. The potential for phosphate being slowly or even suddenly released; caused a temperture, pH, or DSB becoming unbalanced, is also a very real danger. In my mind the question is, not will it happen, but when will it happen. To address it you can go bare bottom and every couple of years cook all your live rock, but I'm hoping to find a better answer.
I believe adding a clean carbon source properly administered will help keep phosphates under control. I'm hoping the increased bacteria film that develops on the live rock helps to slowly extract phosphate or at least keeps them from becoming an unwanted source of increase nutrient release. The success of the ZEO process by many advocates demonstrates carbon addition and increased bacteria extraction has merit in maintaining a low nutrient tank.
Maybe NPR can take it another step.....maybe not. At this point it works for me. As you so well stated, using alcohol with a DSB may cause other issues I have not taken into account. I believe using NPR to extract phosphate has more potential reward than risk if done cautiously. Alcohol is a naturally occuring organic chemical in nature and not a totally foreign additve as often indicated in discussions. I do not believe dosing small quantities of a clean carbon source that is used to stimulate N&P consumption by bacteria will have any long term negative affects.
Unlike the ZEO process, I have no commercial interests in the Vodka or filter floss business. I'm only trying to stimulate thought and advance the hobby. :badgrin: :lol:
