How much Mg does your SPS reef use?

[scyphozoa]

About how much Magnesium (beyond what comes in your salt mix) do you add to your system weekly to keep levels at a steady number (please specify size of tank)?
Do you have a lot of calcerous algae?
--Just trying to get an idea of how fast Mg declines in typical SPS systems.

 

[trueblackpercula]

I am sure it has to do with how much your sps are drawing from the system.

 

[scyphozoa]

Anyone have any numbers....ml s per week?

 

[JB NY]

Don't know. The only time I have ever needed to supplement mg is when it was deficient from the salt I used to do water changes. Other than that I never have to touch it.

 

[cfishrun]

Over the past 3 months I've been working to get my Mg up from about 1050 by adding 15-20 tsp. of Seachem's Reef Advantage Magnesium with every water change (Mg level is currently around 1245). I have a 75g with a total system volume around 140g. I've been pretty consistent at doing 7-10 gal. water changes every week. I used to use Crystal Sea's Bioassy Mix, but because the levels tested low and it was a pain to come by, I switched to IO. I've been gradually converting, and my water changes are now 85-90% IO.

 

[woodywoo]

I use about 4 tbsp every two weeks. But I don't have a super heavy load yet.

 

[JB NY]

<a href=showthread.php?s=&postid=7198633#post7198633 target=_blank>Originally posted</a> by cfishrun
Over the past 3 months I've been working to get my Mg up from about 1050 by adding 15-20 tsp. of Seachem's Reef Advantage Magnesium with every water change (Mg level is currently around 1245).

FWIW, I've raised it many times fom ~1000 to 1400 in a week or two without any problems.

 

[MiddletonMark]

I don't regularly suppliment Magnesium in my 58g.

When I've tested I've not found it to be significantly down, except a few years back when my salt mix tested low in Mag [then I added some to freshly mixed ASM before a w/c].

 

[SaraB]

I've started dosing in Feb with Kent Tech M when I found it to be 1080 in the tank. The bucket of Reef Crystal I was using had a low level at 1020 so that was not helping. Every RC bucket since then has been higher at around 1285, but I still dose for every water change and the entire tank is currently at 1350.

I suggest testing your new water change water with each bucket of salt that you open to find out your levels since you may be depleting your tank of the levels by doing water changes.