I'd like to have a discussion on just nutrients. Everything below is under the assumption that all other parameters are stable and in the proper range and that you have suitable lighting.
I have read a good bit on the nutrient requirements of coral over the last couple years. Without getting too technical and long winded... I know on most every coral reef across the globe, the nutrient level in the ocean water column is near nonexistent. I've also seen it mentioned in studies that these samples are usually taken in a specific time of the year, under the most ideal conditions. There is hope they can get more samples taken at different times of the year, like the rainy season, to compare values. At the moment, there is not a lot of information regarding runoff at reefs near smaller land masses. What is somewhat known is that there are times when more nutrient rich water is driven up from the ocean depths. This can happen during major storms or at times when there are large scale changes in the ocean currents. The wide time frames between occurrences should also make them an exception and not the rule as far as we're concerned (That is unless you stir things up the way I describe below). We all know that there are lots differences to wild coral reefs in open oceans vs our minute tanks. But one big difference is that on the reefs there are frequent phyto & zooplankton blooms that happen at night. These wild corals get most of their organic nutrient requirements from feeding on these nighttime blooms that our tanks don't naturally have.
I believe that in a ULNS system, sometimes the nutrients are taken up faster by the export method the aquarist has implemented, and the coral do not get enough, fish or no fish. Otherwise why are some people seeing muted color with poor growth and others are thriving? There must be some other common denominator between those having issues with a ULNS and those that aren't. In my mind that has to be feeding, nothing vs direct or broadcast coral feeding. I have seen the results of people that have had zero nutrients in the water and struggle with color and growth. But I don't know if or how much they feed their coral specifically. The common thing said to these people is feed more, add more fish or dose. But I seldom see it asked if they feed the coral. If these people do start dosing NO3 and possibly some PO4 the corals bounce back pretty quick and color up.
I initially thought that I didn't care about nutrient levels as long as they didn't get too high and there were no issues, like GHA, Diatoms or other nuisance algae. I have never been a big coral feeder. I did use some of the FeedMeAlgae products for a time, but I was never very consistent. At the same time my nutrients were seldom ever at or near zero and it's not something I'd ever striven for. Other than dosing amino's, coral feeding for me has been creating a detritus storm a couple times a week after lights out or what the coral gets from uneaten fish food. The more I think about it the more I think keeping higher nutrient levels puts us much closer to the tipping point where something bad happens. Why not keep things lower and keep the coral happy and colored up at the same time? This gives us more time to react if things start to climb.
I'd like to hear from everyone, whether you run ULNS or not.
What are your NO3 & PO4 levels?
What do you primarily feed the fish, Pellet or Frozen?
Do you regularly feed your corals?
If so, how often and what time of the day?
What products do you use to feed coral?
Are you happy with the coral appearance?
Do you have reoccurring algae issues?
I have read a good bit on the nutrient requirements of coral over the last couple years. Without getting too technical and long winded... I know on most every coral reef across the globe, the nutrient level in the ocean water column is near nonexistent. I've also seen it mentioned in studies that these samples are usually taken in a specific time of the year, under the most ideal conditions. There is hope they can get more samples taken at different times of the year, like the rainy season, to compare values. At the moment, there is not a lot of information regarding runoff at reefs near smaller land masses. What is somewhat known is that there are times when more nutrient rich water is driven up from the ocean depths. This can happen during major storms or at times when there are large scale changes in the ocean currents. The wide time frames between occurrences should also make them an exception and not the rule as far as we're concerned (That is unless you stir things up the way I describe below). We all know that there are lots differences to wild coral reefs in open oceans vs our minute tanks. But one big difference is that on the reefs there are frequent phyto & zooplankton blooms that happen at night. These wild corals get most of their organic nutrient requirements from feeding on these nighttime blooms that our tanks don't naturally have.
I believe that in a ULNS system, sometimes the nutrients are taken up faster by the export method the aquarist has implemented, and the coral do not get enough, fish or no fish. Otherwise why are some people seeing muted color with poor growth and others are thriving? There must be some other common denominator between those having issues with a ULNS and those that aren't. In my mind that has to be feeding, nothing vs direct or broadcast coral feeding. I have seen the results of people that have had zero nutrients in the water and struggle with color and growth. But I don't know if or how much they feed their coral specifically. The common thing said to these people is feed more, add more fish or dose. But I seldom see it asked if they feed the coral. If these people do start dosing NO3 and possibly some PO4 the corals bounce back pretty quick and color up.
I initially thought that I didn't care about nutrient levels as long as they didn't get too high and there were no issues, like GHA, Diatoms or other nuisance algae. I have never been a big coral feeder. I did use some of the FeedMeAlgae products for a time, but I was never very consistent. At the same time my nutrients were seldom ever at or near zero and it's not something I'd ever striven for. Other than dosing amino's, coral feeding for me has been creating a detritus storm a couple times a week after lights out or what the coral gets from uneaten fish food. The more I think about it the more I think keeping higher nutrient levels puts us much closer to the tipping point where something bad happens. Why not keep things lower and keep the coral happy and colored up at the same time? This gives us more time to react if things start to climb.
I'd like to hear from everyone, whether you run ULNS or not.
What are your NO3 & PO4 levels?
What do you primarily feed the fish, Pellet or Frozen?
Do you regularly feed your corals?
If so, how often and what time of the day?
What products do you use to feed coral?
Are you happy with the coral appearance?
Do you have reoccurring algae issues?
