Finally an easy solution to bryopsis!

TWallace

New member
I've battled for many months against this vile weed. Nothing I tried would eat it. I tried lettuce sea slugs (they eat it but not fast enough to control it), sea hares (aplysia sp.), almost every kind of snail commonly available in the hobby, 3 kinds of dwarf hermit crabs, emerald crabs, a small blue lined rabbitfish. Only the lettuce sea slugs ate it, but they only suck the chloroplast out and the plant still grows fine despite this. Plus they are easily killed by even the weakest of powerheads. I couldn't keep them alive in my main system due to the filtration and current.

Everyone kept saying there must be a nutrient problem or bryopsis wouldn't grow. This sounds good at first, but makes no sense when tests consistently show 0 nitratres/phosphates and you have a refugium with chaetomorpha growing. Cheato should eat up the nitrates/phosphates and keep your tank clean, right? My chaeto was getting choked out by bryopsis. Bryopsis needs extremely little light and nutrients to get by, even less than chaetomorpha needs. If a healthy tank (low nutrients) allegedly can not sustain bryopsis, then how is it logical to believe the same system can sustain chaetomorpha? Lowering nitrates/phosphates was not an option. I started using a phosban reactor, but how do you reduce phosphates beyond zero? This was a wasted investment, but at least it was cheap.

Then I stumbled on to this thread at Reef Frontiers. Mojoreef suggested boosting magnesium to 1500-1600. I don't understand the chemistry behind this, but for some reason the bryopsis absorbs the magnesium and it prevents it from growing. I didn't believe it at first, it was too easy. But it was cheap, so I gave it a shot. I ordered some Kent Tech M. I already had a magnesium test kit, and my mag always measured somewhat low (around 1100). I started boosting it up and within days the bryopsis turned translucent yellowish brown and started falling apart. I accidentally overshot my goal of 1550 magnesium and went to 1680ppm. Here are some day by day snapshots starting when the magnesium reached 1680:

Day 1
bryopsis.jpg


Day 2
bryopsis2.jpg


Day 3
bryopsis3.jpg


Day 4
bryopsis4.jpg


I later regretted picking this spot in the tank to document the bryopsis decline because the rock is covered with green zoanthids underneath the bryopsis. So as the bryopsis dies and falls off the rock, it still looks green on the rock, but it's the zoanthids you're seeing now, not the bryopsis.

At the same time, chaetomorpha in my refugium looks dark green and healthy. The bryopsis that was choking it is now all mushy and yellow.

I'll continue to update this thread with pics of my dying bryopsis if there's interest.
 

chewie

New member
Good ol' MOJOREEF!

I will forward this info to the people I know who have briopsis.

Have you noticed any ill effects from the elevated Mg?

Thanks for sharing.
 

TWallace

New member
Nope, no ill effects from the mag. All corals, fish and inverts still look and act normal. The biggest surprise to me is that the chaeto in the fuge deals with the magnesium fine, but bryopsis is killed by it.
 

TWallace

New member
It actually boosted my calcium to 500. Alk got lowered to 7.7dKH, but I've since used some Kent Superbuffer dKH to put it right.
 

Peter Eichler

New member
Very interesting... I had a small bryopsis problem and was doing the usual things to battle it, mainly low nutrient input and lots of nutrient export. However, about the time I actually overcame it I accidentally overdosed my magnesium to the tune of 2200+ ppm. I never thought that it was more than just a coincidence. FYI, boosting it to 2200 had no ill effects on any other inhabitants.
 

Rhodesholar

New member
I think this is a great idea but what I am having trouble with is that water can only hold so much in solution. I am suprised to hear that your other parameters were within reef specs with that high of Mg. Very interesting. Great information. Thanks.
 

frederickk

New member
Thanks for the info. I'm am battling bryopsis as well and feel it's spreading all over the tank.

How much Kent Tech M did you have to use in your 55g at a time.
i'm trying to figure how much I need for my 400g total system?
 

TWallace

New member
I bought a 64oz bottle of Tech M and used about 75-80% of it to boost magnesium from 1100 to 1680 in my 55g tank (you probably only need around 1550 to kill the bryopsis, I overshot it). Tech M is also sold in 128oz (1 gallon) bottles for $19 on Marine Depot. For larger tanks, you can also buy Mag Flake (Magnesium Chloride, which is used as a de-icer, available at some hardware stores). But using commercial de-icer in a reef tank scares the crap out of me, so I avoided that.

For adding Tech M, the bottle recommends only 1ml per gallon per day, which will boost your system by 18.3 ppm per day. In my case, I needed to raise it from 1100 to 1550pm, so it would have taken nearly a month to get it where I needed it (450ppm / 18.3 per day = 24.5 days). So I was adding 4-5 times that amount, to boost magnesium by about 80-100ppm per day. I'll take another pic of that same rock when I get home tonight.
 
Last edited:

RichConley

New member
<a href=showthread.php?s=&postid=9869867#post9869867 target=_blank>Originally posted</a> by TWallace
But using commercial de-icer in a reef tank scares the crap out of me, so I avoided that.

I'd be willing to bet a large amount of money that the Kent is nothing but commercial de-icer with water added to it.
 

webbstock

New member
Mg is a key element in photosynthesis. Specifically, Mg ions allow chlorophyll molecules to form. Early studies demonstrated that increasing Mg concentrations dramatically increased CO2 consumption and O2 production by chloroplasts.

With most enzymatic reactions a little of X is good and too much is bad (in this case X=Mg). I'm guessing that the bryopsis is more sensitive to the Mg levels than your chaeto. Perhaps its chloroplasts are more "efficient" than the chaeto's (Also a reason why low light might not bother the bryopsis) and thusly more sensitive to the increase in Mg. Either way, I'm glad it's working out.
 

MTB

New member
I have been battling bryopsis for months. Just when it looks like I am getting a handle on it, it comes back strong as ever over night. I may have to try this.
 

TWallace

New member
<a href=showthread.php?s=&postid=9871174#post9871174 target=_blank>Originally posted</a> by MTB
I have been battling bryopsis for months. Just when it looks like I am getting a handle on it, it comes back strong as ever over night. I may have to try this.

I feel your pain. I struggled with this horrible affliction for many months (nearly a year now). This magnesium trick works fast and as far as I can tell has no terrible side affects (it will probably lower your alk a bit, but raise your calcium).
 

jdieck

New member
<a href=showthread.php?s=&postid=9869512#post9869512 target=_blank>Originally posted</a> by frederickk
Thanks for the info. I'm am battling bryopsis as well and feel it's spreading all over the tank.

How much Kent Tech M did you have to use in your 55g at a time.
i'm trying to figure how much I need for my 400g total system?
Use the linked calculator to determine how much magnesium supplement you need to add. I would recommend not to increase magnesium more than 100 ppm per day and to keep it at a maximum level of 1600 ppm. After the Bryopsis is gone try maintaining a regular level of 1300 ppm

http://home.comcast.net/~jdieck1/chem_calc3.html
 
Top