So, back to dinoflagellates. A recent report in the literature suggests that at least one species has unusually poor internal pH control and consequently showed poor growth as the external pH changed from its "optimal" level. Two marine dinoflagellates, Hulburt and Stein, were shown to stop growing as the pH dropped from 8 to 7. When the external pH was reduced from 8 to 7, the internal pH of dropped from 7.92 to 7.04 ( dropped from 8.14 to 7.22). The researchers attributed the change in internal pH as the cause of the reduced growth. While this experiment involves a pH reduction rather than an increase, and while it is not likely the same species that infests some reef aquaria, it does show that changes in dinoflagellates' internal pH may make them susceptible to changes in external pH that do not as strongly impact other types of organisms.
he pH of a reef aquarium significantly impacts the health and welfare of the organisms that call it home. Unfortunately, many factors tend to pull the pH out of many commonly kept organisms' optimal range. Low pH is the most common problem, and its causes and necessary corrective actions have been discussed in a . Excessively high pH, however, can also be a significant problem in some aquaria. In addition to potentially impacting the aquarium inhabitants' health, high pH can lead to other problems, including the precipitation of calcium carbonate on objects such as heaters and pump impellers. Such precipitation can also artificially cap the attainable levels of calcium and alkalinity. For these reasons, pH is a parameter that aquarists should monitor.
Optimal Conditions for Algae Growth
here are several reasons that aquarists would want to monitor pH in marine aquaria. One is that aquatic organisms thrive only within a particular pH range. This range certainly varies from organism to organism, and it is not easy to justify a claim that any particular range is "optimal" for an aquarium containing many species. Even natural seawater (pH = 8.0 to 8.3) isn't likely to be optimal for every creature living in it, but it was recognized more than eighty years ago that moving away from the pH of natural seawater (down to pH 7.3, for example) is stressful to fish. We now have additional information about many organisms' optimal pH ranges, but the data are inadequate to allow aquarists to optimize the pH for most organisms in which they are interested. Additionally, the effect of pH on organisms can be direct or indirect. For example, the toxicity to some organisms present in our aquaria (such as mysids and amphipods) of metals such as copper and nickel is known to depend on pH. Consequently, the pH ranges that are acceptable in one aquarium may be different from those ranges in other aquaria, even for the same organisms.
Ecophysiology of coffee growth and production - SciELO
The Exo Terra Reptile UVB100 emits optimal levels of UVB, similar to that of shady environments such as rain forests or other tropical locations. Reptiles living in these habitats receive moderate UV radiation due to climatological conditions (fairly high humidity, changes in weather, etc) that prevent unfiltered sunlight from reaching the reptile’s basking site. The optimal Vitamin D3 yield index ensures vitamin D3 photosynthesis to aid calcium absorption and prevent metabolic diseases.
Ecophysiology of coffee growth and production
Under moderate temperature conditions when C3 plants have sufficient water, the supply of carbon dioxide is abundant and photorespiration is not a problem. The CO2 concentration of the atmosphere as of 2004 was about 380 ppm and this CO2 freely diffuses through the stomata of leaves and across the membranes of the while water diffuses out through the stomata. But during hot and dry conditions, the stomata close to prevent excessive water loss and the continuing fixation of carbon in the dramatically reduces the relative concentration of CO2. When it reaches a critical level of about 50 ppm the rubisco stops fixing CO2 and begins to fix O2 instead. Even though the detoured process feeds some PGA back into the cycle, the photorespiration process causes rubisco to operate at only about 25% of its optimal rate.
Ecofisiologia do crescimento e da produção do cafeeiro
Adding vinegar is another option for reducing pH. It has two actions that lower the pH. The first happens instantly, as the acetic acid releases H to the aquarium water (a process called ionization):