How high of Magnesium can corals withstand safely?

[ryangrieder]

sadly, i am starting to get bryopsis again. i know i had a whole other huge thread about killing it with magnesium about half a year ago, and it worked great! butt... that was a fish only tank. this time i have a full reef tank. i know in order to kill bryopsis with magnesium, i have to dose every day with tech M and bring it up to around 1800-2100 ppm. this killed bryopsis instantly last time, but now im scared because of all my corals and i cannot relocate them because i have wayy to many to relocate.

so, do you know what level of magnesium will corals start to show signs of stress and/or start to die? like i said, im planning on going up to 2000ppm...

 

[NITECRAWLER]

water changes every 2 days
way tooooooo high

1500 -1800 is way to high
why would u bring it past 1400 ?

 

[Macropora]

I've had it as high as 1750 ppm using BRS Magnesium for about 2 months before the bryopsis started dying off. After 6 months, the nutrients started to build up again and this stubborn algae came right back. Never went up to 2000 ppm.

 

[Jzhou]

I fought off filament algae in one of my smaller reef tanks by bringing the magnesium level to 1800 a few years ago. Aside from some snails and hermits dying, the corals didn't seem to take any ill effect. To make sure all the algae was gone, I followed this by blacking out the tank for 4 days directly after the elevating the mag levels. Some people have also used ethanol to fight off hair algae in their reef tanks. I have heard a lot of success stories, but I don't recommend it because the extra oxygen sometimes even burns the gills of fish.

 

[ryangrieder]

water changes every 2 days
way tooooooo high

1500 -1800 is way to high
why would u bring it past 1400 ?

Water changes every 2 days? What?

And 1500-1800 is not high if your doing it to kill bryopsis. My mag level is always 1450. Now that I'm going to raise it to kill the bryopsis, i need to be around 2000

 

[ryangrieder]

I've had it as high as 1750 ppm using BRS Magnesium for about 2 months before the bryopsis started dying off. After 6 months, the nutrients started to build up again and this stubborn algae came right back. Never went up to 2000 ppm.

So, you brought it up that high, and left it like that for 2 months? Thennn started to seem die off on bryopsis? Did you have coral in the tank?

 

[ryangrieder]

I fought off filament algae in one of my smaller reef tanks by bringing the magnesium level to 1800 a few years ago. Aside from some snails and hermits dying, the corals didn't seem to take any ill effect. To make sure all the algae was gone, I followed this by blacking out the tank for 4 days directly after the elevating the mag levels. Some people have also used ethanol to fight off hair algae in their reef tanks. I have heard a lot of success stories, but I don't recommend it because the extra oxygen sometimes even burns the gills of fish.

Well, I'm actually using red seas po4 chemical, which main chemical in the product is ethanol. So far noting. If anything... I could be crazy, but it's gotten worse. As in my Phos levels have not changed while using it and now I'm seeing cyno.

Few hermits and snail die off no biggy, but your corals were stable? That's good to hear. I plan on going to 2000ppm. Previously when I sent to 2000, within a week they started turning gray, then white, then disappeared...

 

[lfsmarineguy]

Little over a year ago I was treating bryopsis in a store tank and had it up to 1900 for at least a week before I started to see significant algae death. The corals never seemed bothered and I kept it elevated for maybe 3 weeks.

I wouldn't use Tech-M though, the Seachem dry magnesium is way better for the tank.

 

[ryangrieder]

Little over a year ago I was treating bryopsis in a store tank and had it up to 1900 for at least a week before I started to see significant algae death. The corals never seemed bothered and I kept it elevated for maybe 3 weeks.

I wouldn't use Tech-M though, the Seachem dry magnesium is way better for the tank.

Great to know. Thank you. But, I thought the issue was that it only worked with Magnesium sulfate mixed with Magnesium chloride? Why is the sachem way better? Last time I did this I used esv magnesium...

 

[ming]

I don't know the tolerance, but I was under the impression the issue is the thing which magnesium is binded with, i.e. sulfate or chloride which you don't want too much of either, but there isn't a pure form of magnesium so you need to dose one or the other. And the suggestion I remember reading is probably to dose a little of both, so you don't have too high concentration of either one, and the concentration is limited through water changes.

 

[Macropora]

So, you brought it up that high, and left it like that for 2 months? Thennn started to seem die off on bryopsis? Did you have coral in the tank?

I had a lot of chalices back then. They did fine when the magnesium was 1750 ppm for two months.

 

[lfsmarineguy]

Besides that dry additives are more cost effective because you aren't paying for water. Some of the liquid magnesium additives can contain amounts of ammonia.

 

[Bryceandmandy]

Besides that dry additives are more cost effective because you aren't paying for water. Some of the liquid magnesium additives can contain amounts of ammonia.

Very interesting, what are some of the ones contain ammonia?

 

[Jzhou]

The ethanol people use in ethanol dosing is normally the ones that are straight out of the drug store. I believe there is a thread on it.