What carbon are you using?

Not sure about either one to be honest.

Thoughts on Mg: IME, Mg technically isn't a problem unless it's very low. I do actively dose Mg I suppose you could call it, but I do it via my water changes: I add just enough MgCl and MgSO4 to my new water to bring it up to around 1500. That tends to keep the Mg in the tank at "good enough" levels. So I don't think "worry" about Mg. It's just a routine.

I don't understand the science behind it, but I've noticed that things just look better when Mg is at "good enough" levels (versus "far too low"). The change is most noticeable in anemones (of which I have a handful). Ever since adopting the water change technique however I haven't noticed them looking off due to Mg levels in probably 4-5 years now or more.

Guess the thing to try is seeing if your Mg is low, then dosing it back to seawater type levels, then see if you notice a difference in your tank.

Thoughts on carbon: I used to think that reactors were a better choice for carbon as I thought water passing through the column of carbon would make for better absorption of the baddies because of better contact to more surface area blah blah blah something or other. But seem to have read more than a few credible articles in the last few years that seem to suggest just having a bag in a high flow area in the sump is good enough because osmosis or something blah blah blah the main take away is it still works as carbon.

I made the investment in TLF reactors so I figure I might as well use them for carbon but if I didn't have them already I'm not sure I'd worry about it too much.

Guess the thing to try is move your carbon into a reactor and see if you notice a difference in your tank. :lol:

Not sure, it's black.

Tony, your ideas give me more time off today, meaning longer nap. I should have had a do nothing option :)

Let's expand on this. What is "very low" and what would the problem be? Mine is about 1150ppm and I don't really see any problems. Looks like a lot of work to chase a number without understanding the problem.

I would have voted for this option as well. Whether you called it, "do nothing" or "keener", it's all the same.

oh, hey, glad you could drop by. How's the clove eating mermaid problem going? Hate when those get in the tank!

In my experience, a result of low mag is that it makes it more difficult or challenging to maintain higher alkalinity levels. There's a whole chemistry lesson you can read up on regarding the relationships but what I took away was simply, low mag will bugger up alkalinity. To me low is below 1200 is when things start to get interesting.

Hmm. Mine is (being generous) ~1170. I'll test alk, pretty sure I have a kit for that :)

IME low mag = unstable Calcium & Alkalinity. Magnesium helps allow for supersaturation of calcium carbonate so the lower the mag the lower saturation level. My understanding is anything under 1200 ppm is low but then again if you're happy with your current Ca and Alk levels then Mag is likely fine at whatever it is even if lower than 1200ppm. However higher mag levels should result in higher efficiency from a Ca reactor and perhaps better growth as well, whether or not this would be noticeable though.... :confused: