Can Someone Give me a Refresher?

[Shy519]

I have an allergy that makes my mind foggy at times and for the life of me I cannot remember certain things at certain times. I'd like to be able to look back at this for reference. What does each parameter affect? What happens when each one gets too high? Too low? Which ones affect fish/inverts/algae blooms? Anything else to know is always helpful!

 

[Ranjib]

Are you looking for chemistry specifically?

 

[laverda]

That could fill a book! Stability is the critical thing with all peramiters. Salinity is a measurement of elements(salts) dissolved in saltwater. Normal saltwater has a specific gravity of 35 or 1.025. Higher salt levels are harder for fish as they have to remove excess salt from their bodies. Elevated salt levels can be benifical for hard corals as their is more ALK, Ca Mag and other trace elements available to them for building their skeletons. Lower salinity has less of these building blocks available. Lower salinity can be benifical to fish as they expend less energy removing salt from their system. It is also detrimental to so pests like ICH and flatworms. Fish can not handle rapid increases in salinity.
The most critical for a reef tank is probably Alkalinity. It also tends to change the fastest. You want to maintain it 7.5- 9 typically. ALK Is the main controlling factor in the PH of a reef tank. Being low contributes to lowPH. A low PH (less than 6.5 PH) can cause coral skeletons and sand to start to desolve. Alk being high will burn the tips or cause bleaching if excessive. It does no affect fish as much as it does corals.