Testing without color or titration scales?

[saltwaterwannabe]

I am looking to test more Mg, Po4, and other measures that I currently do not have tests for. I have always had a very hard time seeing the color and titration tests accurately so I am looking for something akin to the Hanna checkers like the Ca, Alk, and Ph that I have. I found one but do not see it on any of the aquarium supply sites which gives me pause about using it.

1) Does anyone know of reasonable options other than color and titration tests for Mg, PO4, etc.?
2) Has anyone used the Exact Idip 570? Here is a link:

 

[chris s]

Hanna does make a low range phosphate checker. Model HI713

 

[saltwaterwannabe]

Thanks, I actually misspoke and called Potassium PO4. I have Ca, Alk, and Phosphate Hanna checkers already. My corals actually look as good as they ever have, but a couple are more orange than the color they had when I bought them and I am certainly interested in seeing how much color I can achieve.

I am hoping to come up with a non-color or non-titration Mg, Fe, I, P, K test since I struggle in gauging the colors against a chart. I am most interested in Mg, but I would like the others so I can consider adding these to see if I can achieve more color. I also have color tests for Ph, No2-, No2+, No3 that I would be interested in replacing, although I very rarely test for these.