Lighting & Cyano

JimCali75 · Jan 31, 2014

I'm using a Kessil A360W about 8" over a 60g cube 24x24. I've noticed a patch of Cyano (red slime algae) forming. Nitrates are close to 0. Got good flow.. I only have the Kessil turned up about half way. Corals seem happy but could the light intensity be to low and encouraging the cyano? I've read that old halide bulbs can cause cyano. Also I run the light duing the night since I'm gone all day . On about 10pm off at 7am. Maybe too much light with the ambient light during the day? Thx for your input

Reefing Madness · Jan 31, 2014

I run my LEDs the same time you do, typically you get the cyano by adding new stronger light, and to much light, and low flow. Whats the flow in the tank? How many powerheads you using?
Excess nutrients also fuel it, its a bacteria, so its a bear to figure out. Phosphate levels?

GHill762 · Jan 31, 2014

cyano is actually a bacteria not an algae.. it's also not caused by light, but light can bring out an underlying problem..

Reefing Madness · Jan 31, 2014

K.R. Timmermans, , B. van der Wagt1, M.J.W. Veldhuis, A. Maatman and H.J.W. de Baar

Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, The Netherlands

Received 11 March 2004; accepted 1 May 2004. Available online 17 November 2004.

Abstract
Experiments were conducted with three species of marine pico-phytoplankton: Synechococcus sp. (CCMP 839), Pelagomonas calceolata (CCMP 1756) and Prasinomonas capsulatus (CCMP 1617) in order to collect physiological parameters for pico-phytoplankton to be utilised in Ocean Biogeochemical Climate Models. The main parameters to follow the effects of ammonium, phosphate, iron and light limitation were cell growth rates (μ), half saturation constants for growth (Km), N, P and Fe quota (per cell or per mol C), and photochemical quantum efficiency (Fv/Fm).

The nitrate and phosphate limitation experiments demonstrated that the small phytoplankton species could grow at low N and P concentrations. Km values were in the micro-molar (NH4+) and sub-micro-molar (PO43−) range. N and P quota were in the femto-molar range per cell and varied from nutrient-deplete to nutrient-replete conditions. Fv/Fm values were only adversely affected at the lowest N and P concentrations in these experiments. In the Fe limitation experiments, it was shown that all three species were adversely affected only at extremely low Fe concentrations. Iron chelating agents had to be added to force the species in Fe limitation till ultimately growth stopped. Km values with respect to dissolved Fe were in the femto-molar range. Fe quota were in the low zepto-molar (10−21 M) range per cell, and varied considerably from Fe limiting to Fe replete growth conditions. Fv/Fm values diminished only at the lowest iron concentrations. In the light limitation experiments, growth rates and photochemical quantum efficiencies were adversely affected only at irradiance levels below 10 μmol photons m−2 s−1. These results indicate that the pico-phytoplankton species will hardly ever be completely stopped in their growth by NH4+, PO43−, Fe or light (separately) under natural conditions.
Physiological responses of three species of marine pico-phytoplankton to ammonium, phosphate, iron and light limitation