[Frank N Beans]

i did a test using a new seachem kit. the tank is a 125gal reef that had a 20gal water change on tues (the test was thur) and a massive water change about 3 weeks ago when i moved the tank to my new house. i used instant ocean salt.

[eses]

Is the test turning blue at all? Even a just a touch? It is possible that it used up all the iodine, but with how recently you did your water change, unlikely. Unless you have many soft corals that are really leeching it out.

Did you calibrate the kit using the sample water they include, and did you make sure to fill the reagent bottle all the way up before putting in the two liquid reagents?

..and, when you fill up the tray with sample water, are you using the smaller dropper tube, and filling up just the tube portion with water? I noticed if you deviate from this even a little it will throw your test WAY off. I'm not automatically saying you did it wrong, but it is the first thing to check as I was coming up with no iodine readings and it turned out I hadn't mixed the reagent #2 right.

Of course, if you've been using your kit awhile and have been getting valid readings off it, and the calibration works, then your probably right on and your tank has no iodine.

Despite popular thought and what I've been told here, I've noticed my iodine lasts about a week in my tank and I do indeed need to either a) do a major waterchange, or b) dose the tank with iodine. My tank is a much smaller system however, only 29 gallon, and I have many large corals. Even with doing weekly water changes I'm finding myself needing to supplement with the iodine just to keep the level at .06 mg/l.


Wes

[Randy Holmes-Farley]

Most people who don't supplement get a zero reading for I- in their tanks using the Seachem kit, IME. Iodide seems to drop from natural levels to undetectable in a few days.

[adron420]

I agree with Randy Holmes-Farley, most say Iodide is used up within 3-4 days. I dose iodine twice a week, I have a salifert test kit and have never got a reading, either my level is very low, my corals are happy so Im not going to dump loads in trying to boost the level, or the test sucks. I have not heard of many having good results with iodine test kits. IMO iodine is a good addition, take that for what its worth