Low iron?

[Cinnebuns]

I've had a few strange things happen in my shrimp tank that nobody has been able to explain to me. While talking to an employee at my LFS he suddenly asked a question that may have nailed it. "Could it be low iron?"

The water source for this tank is unique to my other tanks because of the shrimp. My tap pours out nuts and bolts at 21 gh which is far too high for shrimp. I got my shrimp from someone on the forums who was keeping them higher gh than people typically do. This was an amazing find for me because it made the gh more obtainable. Rather than having to use RO water, I simply have to let the water sit in a bucket for 24 hours and scoop it off the top. The minerals then sink to the bottom. I get 14 gh water this way. I'm wondering now if that also means I'm losing too much iron. It makes sense because from what i know, iron is heavier than calcium and magnesium. 

The issues I've been seeing in the tank is around plants and algae. Anytime I try to add plants to the tank, I immediately get a spike in brown algae on the walls. Nowhere else, just on the walls. Then, the plants die. I have been able to keep flame moss and marimo moss balls in the tank but all other plants, including duckweed, die. Recently, I tried an unidentified hygrophila from my main tank and that's actually growing. 

After these thoughts I did add some iron suppliment to the tank. I'll see what happened. Anyone else have any insight or thoughts?  

Here's a pic of that hygrophilia for reference 

Edited January 15, 2023 by Cinnebuns

[nabokovfan87]

What is your PH?  Iron issues usually coincide with a particular type of iron being dosed in as well as PH being higher.  I'll try to track down the post with the details.