Most of our new gadgets and gizmos for water chemistry have finally come in, so we have started testing them out. Some of the kits we ordered include tests for nitrate, nitrite, phosphorus, chlorine, hardness, sulfate, and iron. At first, we were testing the kits out on tap water to get comfortable with all the tests, and then Matt collected sea water samples from one of the tanks so we started using those.
Today I tried the nitrate kit, which has never been used before. It was a surprisingly simple and quick test, and I found 79.5 ppm (mg/L) nitrate in the sea water. Unfortunately, I do not know the significance of this value, so David suggested that I try the test on tap water for comparison. The amount of nitrate in the tap water sample was 23.2 ppm (mg/L). According to Wikipedia, marine aquariums are only supposed to have trace amounts of nitrate in order to be healthy, so I do not know what our values mean.
A few of the kits we ordered do not have the range to collect values from sea water, so we are thinking of diluting our sea water samples with DI water. We will then use that mixture to conduct the tests that did not work (i.e. the phosphorus and hardness tests). In order for this plan to work, however, there must be small amounts of chemicals in the DI water or our data will be skewed. I checked the level of phosphorus in the DI water and the value came out to be 34 ppb. I am not sure if this means that our dilutions will work, but I am sure we will be able to figure out how to analyze our data after doing some more research.