Randy Holmes-Farley
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Reef Chemistry Question of the Day 298
We all know that organisms from bacteria to whales require many different trace elements for the biochemical processes of life.
One of the things we don't always have a good handle on in a reef tank is where they are coming from and where they are going.
It is common for folks to assume that water changes are an important way that trace elements get into a reef tank.
But when not dosing them, are water changes the main way?
There have been studies of the relative contribution of trace elements from foods and water changes (e.g., by Ron Shimek):
but some aspects of those results (and the data they are derived from) make me skeptical of some of the results.
So let's use more widely recognized sorts of public data.
Here's the question.
Which adds more iron to a 100 L reef tank that is completely depleted in iron:
1. A 100% water change with natural seawater, which we will assume for this purpose has a concentration of 0.5 nM or 28 ng/L = 0.028 ug/L
2. 1 medium shrimp (size 41-60/pound)
3. Nori sheet 7" x 8"
4. 1 whole sardine (2-2/3" x 1/2" x 1/4")
Note that the question is not asking about bioavailability or even how much of the iron ends up in the water after some period of time, which would be complicated for all of the choices, but just how much total iron enters the aquarium via these means.
Feel free to guess.
Good luck!
Previous Reef Chemistry Question of the Day:
We all know that organisms from bacteria to whales require many different trace elements for the biochemical processes of life.
One of the things we don't always have a good handle on in a reef tank is where they are coming from and where they are going.
It is common for folks to assume that water changes are an important way that trace elements get into a reef tank.
But when not dosing them, are water changes the main way?
There have been studies of the relative contribution of trace elements from foods and water changes (e.g., by Ron Shimek):
but some aspects of those results (and the data they are derived from) make me skeptical of some of the results.
So let's use more widely recognized sorts of public data.
Here's the question.
Which adds more iron to a 100 L reef tank that is completely depleted in iron:
1. A 100% water change with natural seawater, which we will assume for this purpose has a concentration of 0.5 nM or 28 ng/L = 0.028 ug/L
2. 1 medium shrimp (size 41-60/pound)
3. Nori sheet 7" x 8"
4. 1 whole sardine (2-2/3" x 1/2" x 1/4")
Note that the question is not asking about bioavailability or even how much of the iron ends up in the water after some period of time, which would be complicated for all of the choices, but just how much total iron enters the aquarium via these means.
Feel free to guess.
Good luck!
Previous Reef Chemistry Question of the Day:
Reef Chemistry Question of the Day #297: Effect of YOUR diet on your reef tank!
Reef Chemistry Question of the Day 297 Unlike nearly other reef chemistry question of the day, I don't even know what direction this answer will come out, and we can discover it together! Suppose you decide to have a late night drink in your living room while you watch your reef aquarium. You...
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