I don’t mean to challenge anybody's experience here. I've heard positive experiences from ultra-low nutrient tanks, and from messy, almost insulting, septic looking high nutrient tanks. What has worked for me is having a refugium with chaeto/caulerpa, lots of pods and amphipods (and a great onslaught of other critters), with bio loaded rocks and an active light cycle between the display tank and the fuge.
When I did chase numbers, my inverts would crash and the tank would end up being an over glorified FOWLR tank. I would routinely check numbers, or check when I'm seeing something going wrong, and it became an obsession. At one time, my BTA's were in a tank with nitrates at 80 with not a speck of algae anywhere, and they never looked better and I still thought I was doing something wrong. In another tank, nothing was growing or keeping color, and the chaeto completely shriveled to a pile of puke, but my nitrate and phosphate numbers were low like everyone said they should be, all while I'm battling Dinos. So nutrients are a good thing right? It was discouraging and stressful. So I’m disinclined to chasing numbers now.
Perhaps it has to do with what we keep in the display tank. LPS, SPS, nems, and clams may do better in lower nutrient tanks, but do we really know? As they consume the nutrients, and we go to test for numbers and get low numbers, are we led to think low nutrients are the way to success, all the while we're heavily feeding our fishes at the same time? I've seen Carpet Nems in tanks that would scare seasoned tank cleaners from even servicing the tank. And I've seen SPS in bare bottom tanks, emaciated fish, without a trace of algae anywhere, and their colors were on point! So it depends on what we're keeping, how much of them we're keeping, and how much they are consuming. So is there a balance that we are not considering when we're all taught to chase numbers? Remember the Redford Ratio? When I fed my nems or corals, they were getting carbon from their food. Carbon may be supplemented in other sources, but forget that for a moment. Carbon consumed from food, plus Nitrate and Phosphate from the water, plus the correct lighting and a healthy population of Zooxanthallae, and voila, a healthy, colorful, clam, nem or coral. Sounds simple, but really its a lot of variables in a crazy balanced equation. So when we delete sources to make our numbers low, are we doing good or are we starving the equation?
I think checking numbers is a good tool to help diagnose what is going wrong when the inhabitants are looking off point. But if the critters, chaeto, rocks, and the beautiful nems or corals are looking good, maybe check the numbers and make a diary entry and move on. Oh yeah, keeping a logbook/diary is a great tool to track what you have done right or wrong as the tank is cycling. Once it's mature and stable, maybe less monitoring of the numbers and more monitoring of the animals is more pertinent. Numbers can be quite obsessive, but letting the system balance out works great or me.
