70s ULNS? What? Nobody even heard of or tried ULNS until Zeovit, carbon dosing and GFO came around about a decade ago - it was long after the internet message board came about. People decades ago just changed water, had a fuge and didn't have names like ULNS -they really didn't even have test kits and could tell that they needed to know about their tank by just looking at it. They also fought less phosphates since nobody used dry/dead rock and had less nitrates since people used sand. This has been written about a few times, but a 197s or 1980s tank was usually more solid and reliable than a tank in the 2000s since people had no ability to tinker and just let nature work. It does seem that people are starting to keep it simple more lately.
Both Phosphates and Nitrates are poisons in high enough of quantities, but both are necessary for life. Too much will first start to inhibit calcification and then lead to death. I would stay under 5 and .1 for optimum growth and color, but you could probably be 5x that high and still have some results. 10x that high and you are going to have problems. The coralline is the first thing to stop thriving when they get too high.
Both Phosphates and Nitrates are poisons in high enough of quantities, but both are necessary for life. Too much will first start to inhibit calcification and then lead to death. I would stay under 5 and .1 for optimum growth and color, but you could probably be 5x that high and still have some results. 10x that high and you are going to have problems. The coralline is the first thing to stop thriving when they get too high.
