explain alkalinity to me?

Could someone explain what alkalinity in the tank means? What it should be and what I can do about high levels?

Thx...

 

alkalinity
Alkalinity is a measure of the water's ability to neutralize acid. This basically tells you how much buffer you have left in your water. Adding calcium supplements will decrease your alkalinity and vice versa; these two need to be kept in a careful balance in order to achieve optimal coral growth.
Try this web site Saltwater Aquarium Setup Guide

 

Thx lunatik. good info and great site. karma!

Right now my tank is FOWLR, no reef/coral/etc but alk seems REALLY high. i dont have the ability to test for calcium yet. I just have 1 damsel in the tank, but he seems to just hide, can be lethargic unless i chase him out of his spots, and am concerned about his welfare. the two turbo snails seems to be loving the tank. All the other numbers seem to be pretty good.

salinity 1.021
NO2 - 0
NO3 - 5
pH - 8 to 8.1

 

Total alkalinity in a home marine aquarium should be between 4-5 meq/l.
Source of information seachem.com and some of my own experience

Jim

 

Do a search for alkalinity and you will see pages of Alk and Ca and Magnesium post I myself have posted a million times about what they are and what they mean and what they do and how to keep the 3 elements all in balance with each other. You have to under stand its reaction with Calcium and how the Magnesium keeps them happily living in harmony with in our fish tanks. There is more to the answer then you might think,

 

For a FOWLR tank, all you need is; PH, NH3, NO2, NO3 and SG. If you want a reef tank, then add the following; Mag, Dkh/Alk, PO4, Str and Cal.

 

Also for a reef tank your salinity is a tad low.....1.024-1.026

 

I might add to Luna's answer. . .

Alkalinity is a measure of a water's ability to retain a given pH. Put another way, it's a measure of how alkaline water is. For example, if acid turns pH towards 0, and alkalines turn pH towards 14, if a water sample is very alkaline, then acid would do less to move it towards 0. Put yet another way, if you took distilled water with a pH of 7, and added an amount of acid, the pH would go down. If you took the same amount of water with a high alkalinity, and added the same amount of acid, the pH would go down less.

If you haven't heard of Randy Holmes-Farley, he's a contributor to this forum on occasion, and has a line of articles called "Chemistry And The Aquarium." You should check them out. This particular article discusses alkalinity.

Hopefully that makes sense. It confuses me sometimes!

 

Very cool. These forums are awesome and you guys are great!

Salinity in the tank up to about 1.023 now. Just two snails and a damsel. The live rock I bought has some colors of something on it. Some purple and some light green. A friend suggested I use Purple-Up. Thoughts?

 

The colors on your rock are coralline algae. They're good, and a sign of good water conditions. However, if the color is on rock you bought, then it's less attributable to your water conditions, and has more to do with the water conditions of where that rock grew up.

Purple up is supposed to enhance those colors, or add to the spread of coralline algae.

In the long run, if you achieve what you want without the use of additives, the results will be all the more rewarding; plus, and more importantly, you add less variables to an already pretty complicated equasion. I've never used it, but I believe that one ingredient in Purple Up is iodine. If you keep adding this stuff just to give you more purple color, think of the amount of iodine you're adding. That's probably not the best environment for corals. Most people on these forums seem to say avoid the chemicals unless there's an emergency. I think that's good advice.

NSW has a salinity of 1.025. Some use higher, some lower. Many say the closest you can get to NSW, the better. If you think about it, it makes good sense. That's where all the corals grew up. Might as well provide them with a similar neighborhood.

Good luck, illushinz!