Is very high iron detrimental to acroporas?

[CTaylor]

Hi,

I just had my water test by ATI with Iron at 39.27 µg/l vs 0.5 'normal'. This is largely b/c I was using a seachem iron test kit that measured my iron level as under 0.1. So dosed it quite a bit often, and it never read more than 0.1. I assumed the chaeto was absorbing it. No. The test kit was bogus. (Assuming ATI is correct) Can iron be a culprit for not being able to keep an acropora more than 10 days? -- They look great for a week (great PE) then decline, STN and or just die. I know there can be other culprits. But this really stuck out. I was also reading that Iron levels should drop quickly. It's also possible my magnet for my fuge light mag light was releasing iron. My other magnets are tunze, which I trust, two SEN pumps and Reef Octopus Skimmer. I havent opened up the SENs ever, they are 1 year in use, but I'm thinking they are ok.

**What is a reliable Iron test?

Thanks

 

[Subsea]

I doubt that you can overdose iron. That is according to Randy Holmes Farley. His article on Advanced Aquaria describes iron in a reef tank.

https://www.advancedaquarist.com/2002/8/chemistry

Iron in Reef Tanks: How Much and What Form?
[Deciding how much iron to add is fairly easy because, in my experience, it doesn't seem to matter too much. Presumably, once you add enough to eliminate iron as a limiting nutrient, extra iron does not apparently cause harm (at least that I've detected in my tanks or heard of from others). I selected a dose of about 0.1 to 0.3 mL of a solution containing 5 g of iron (as 25 g of ferrous sulfate heptahydrate) in 250 mL of water containing 50.7 g of sodium citrate dihydrate. This liquid is dosed 2-3 times per week to my system with a total water volume of about 250 gallons. This iron(II) citrate has turned brown and cloudy since I first made up the bottle years ago, suggesting that it is oxidizing to iron(III) and some is precipitating from solution, but I still use it. Over the past 4 years, I've dosed nearly all of the 5 grams of actual iron to my tank.]


On a side note, the article describes iron storage mechanism that releases iron back to
plant, seaweed or coral when iron is low in water column.