Sometimes our fish eat better than we do...
I think I actually gave myself food poisoning last week by not washing my hands well after feeding the fish.. Not sure if it was that or just good old gastro..
Corals are looking very good Matt, well done.
Thanks, Scott! The tank is coming along.. It's getting there..
Thank you,take your time. You are already very generous of yours. No big deal as I am busy building a shrine in your honour.
Ahhh a shrine! Nice a shrine to fish stench and the aroma of acropora slime... Thanks!
7 cubes twice a day as in 14 cubes total? Of seven cubes spread out over 2 feedings a day? What is your total volume? Seems like a ton of food!
Hey Mike, 14 cubes a day, 7 per feeding. It is a lot of food! 300 gallons.
Those fishes are spoiled! I'm always to lazy to defrost food.
I don't defrost, I just grab the frozen cubes and hold my fistful o' fish food in the tank and let it melt.. Creates quite the snow storm!
Ok Rene... Here goes......
It's funny that a discussion about the amount of food I add coincides with a question about nutrient control! Talk about perfect timing.
Rene, as you know there are many ways of setting up a well balanced reef. Whether it's the old fashioned way: skimmers, sand beds and fuges or the more 'modern' way: Carbon dosing.. The one constant is bacterial maintenance. When using a fuge, algea plays a role in nutrient reduction as well and when your tank is really full of corals, but ultimately, the bacteria that consume nutrients are the most efficient (sometimes too efficient) means of nutrient control.
In my case, what lead to the title of this thread was my over use of 'modern' methods and chasing numbers too aggressively. I say 'too aggressively' because I don't really think chasing numbers is a bad thing unless it is done without patience and keen observation or if the numbers one is chasing are too extreme.. I was not entirely clear on what I was doing and I was overdoing it.. Not to mention just making to many changes all at once and not waiting long enough to see if what I was doing was really helping or hurting..
I find that after a crash in the tank, which usually takes a day or two to be catastrophic, we think that our mitigating actions will have positive effects in as short a time as the bad stuff happened but that is just not the case. The bad stuff takes days to happen but the good stuff takes MONTHS..
Anyways! The short answer to you question is that when bacteria are fed a carbon source, they begin to multiply as they absorb nitrate and phosphate to grow- along with the Carbon source. But bacteria need all three things to flourish. Kind of like how people need air, water and food to survive. If you take away one of those three things, we eventually die. Bacteria are the same. (Sort of.. Iron also plays a part in here but for simplicity's sake, I will leave it out..)
So if you are Carbon dosing and you run out of either nitrate or phosphate, the bacteria stop flourishing and stop consuming the other one that is still present and, in fact, in the absence of one of those two, the other can actually begin to climb.
9 times out of ten, it is nitrate that bottoms out first. This is called being nitrate limited. And of course, when phosphate goes to zero, you are phosphate limited.. The growth of the bacteria populations are unable to continue to expand because there is no more available nitrate or phosphate.
In your case, it seems that your phosphates are dropping more quickly than nitrates, but they haven't completely bottomed out yet..
In either case, which ever nutrient has gone to zero, the only way to continue the process of bringing down both nutrients is to add extra of the nutrient that bottomed out. This allows the bacteria to continue growing and consuming both nitrate and phosphate.
In your case, if your system really becomes phosphate limited, you may have to add some form of phosphate.
The only way to really be sure of a phosphate (or nitrate) limited system is when you see your phosphates (or nitrates) read 0 on all your tests and you see nitrates (or phosphates) stop coming down.
So, as for my system, it has always - I mean always had difficulty reducing phosphates.
I think this has to do with the fact that most of the live rock I used came from a 10 year old fish only system and then sat in my driveway for two years before I finally washed it with a hose and put it in my tank... Yes... I know... Stupid.. Yes.. Stuuuupid!!
I think that all of my persistent cyano issues and bubble algea and bryopsis are due to this crappy (nice looking but loaded with phosphate) live rock I used.
Anyways in this current system, (after my total disaster) I started using vsv (vodka, sugar, vinegar) to control nutrients and then I moved to all in one biopellets. All the while, struggling to keep phosphate under control by adding Astra forms of nitrate (either calcium or potassium nitrate) Then, about 9 months ago I decided to go back to the old fashioned methods and use, as Daniel always called it, BIOLOGY to take care of nutrients.
I beefed up my deep sand bed, added some matrix and really beefed up my cheato fuge. This was working fairly well for quite some time but as I added more and more fish, I watched as nitrates crept lower and lower and phosphates stayed only ok at around .07-.12. This is higher than I would like to have them with all my algae issues..
I started to use some phosphate removers which worked ok but I'm not crazy about spending the money on all the phosphate remover when bacteria can consume it so much more efficiently..
In anticipation of beginning to dose a carbon source, I removed the phosphate absorbers... my phosphate quickly went up to .16-.18..
I removed the phosphate absorbers because I didn't want to get false readings while trying to reduce phosphate with bacteria.
So! About 6 weeks ago, I started dosing aquaforest's np pro (their carbon solution) to drop nutrients but I knew that my nitrate was already below 1ppm and it wouldn't be long before my system became nitrate limited. To deal with this, I started dosing nitrate at the same time as the np pro.
I started out at 5 drops of np pro and a small amount of potassium nitrate..
Nitrates climbed a bit but phosphates stayed up at .18..
So I added another drop of np pro and a bit more nitrate.. Each week I have been testing n and p and watching where they are. And adding a drop more np pro.. I am trying to maintain a nitrate level of around 3 ppm and get the phosphate to begin dropping.. I'd like to get phosphate to around .03-.05.
At the moment I am up to 10 drops of np pro (in my 300 gallon, heavily fed and stocked tank) and alternating between a good amount of calcium nitrate and potassium nitrate.
I haven't checked my p in about a week but when I was at 8 drops np pro, p was still hanging in at .16.
Maybe, I'll get a chance to test tonight.. I've been so busy lately, I haven't had time to hang around RC very much, lately. Or test my tank.. I am eyeballing it, though and the corals are doing great.
I hope this makes sense, Rene! Sometimes hockey practices come in handy for writing small essays on reef central..
