Iodine levels in the water column and Iodine Test Kits

[purplereef]

Up until very recently, some of my corals have had just drab colors (specifically the red millepora/prostrata). My params for dKh, Mg, Ca, salinity are all in the NSW ranges. One of my friends suggested that I check out my iodine/iodate levels.

Does anyone regularly test iodine ion levels in their water? I've been testing for a few weeks now (once per week) after a weekly addition of six drops of Lugol's solution for my ~400-450 gallon system. I've not been able to detect any iodate in the water. Since iodine/iodate supplementation via Lugol's addition can quickly get into dangerous territory, I'm trying to stay patient and raise things slowly. Seeing nothing at all via the test kit is well...disappointing.

Does anyone regularly supplement iodine ion? If so, what do you use? For those that do measure, what levels do you measure in your tank?

Some helpful information.

1) I'm using the Salifert kit which expires in 2013, so I assume that the reagents are still good.
2) dKH = 8.0, Mg = 1250, Ca = 400, refractive index of the water is 1.024.

 

[tuberider]

I have no experience with iodine or iodine kits, you do state though that your parameters are NSW levels, NSW has a higher sg than 1.024, it's more like 1.026.

IME red Acros need a ton of light to fully color up.

 

[bondolo]

I was wondering about iodine as well and asked a while back about test kits. I had two emerald crabs fail to molt successfully in a three month period and iodine was reputed to be important to proper molting.

The answers I got were that consumer iodine tests were terribly inaccurate and essentially pointless. Also, the levels of iodine required are very low so adding any amount is hard to get right. Without a good test to measure depletion you can't determine how much to add.

The most often answer seems to be to use a good salt mix and do regular water changes to keep the iodine levels up. (Some people say this is the answer for magnesium and other trace minerals as well). I supplement a very small amount of iodine because I bought a bottle of the fancy Aquavitro "Ions" before doing any research on iodine. Because of my overcautious usage this is probably having no measurable effect on iodine levels in my tanks (1/4 of "standard" the weekly dose). The Aquavitro product seems to be just dilute Lugols.

 

[rygh]

A few years back I was given some advice a while back to test iodine in order to improve coralline growth.
Note that it has been proposed that the reason Purple Up sometimes helps is because it has iodine in it.

The test is a bit of a pain. Not hard, but more work than usual alk/ca.
My iodine levels were way low. Barely readable.
So I carefully added iodine, to bring it to the recommended level.
I think there might have been a bit of a difference, but not huge or particularly quantifiable.
Maybe a slight increase in coralline growth.
My shrimp seemed to molt at the usual rate, so no obvious difference there.

I still check iodine, but maybe once a year.

 

[purplereef]

I have no experience with iodine or iodine kits, you do state though that your parameters are NSW levels, NSW has a higher sg than 1.024, it's more like 1.026.

IME red Acros need a ton of light to fully color up.

1.024 is in the range, so I'm not overly concerned, but I'll look into raising it over time.

I'm running 4 x 400 watt Radiums, so I'm pretty sure that I have plenty of wattage.

 

[purplereef]

The answers I got were that consumer iodine tests were terribly inaccurate and essentially pointless. Also, the levels of iodine required are very low so adding any amount is hard to get right. Without a good test to measure depletion you can't determine how much to add.

This is what I was worried about. Another $50 lost.

I've seen similar results with Salifert's Phosphate test. At this point, I really don't trust any of their qualitative tests (tank water + add some liquid, and then look at the color). The titration tests seem to be more accurate to me.

 

[Piper]

This is what I was worried about. Another $50 lost.

Is there a concentration of the Iodine listed on the packaging? If so you can check your test kit by adding a measured amount of the supplement to a volume of RO water. You'd have to do the math to figure out what the concentration should test out at but that would tell you if your kit is accurate of if you did in fact just waste $50

~Charlie