Bryopsis Algae Control Method Worked
A while back I posted on a method for bryopsis algae control, that involved using Kent Marine’s product Kent Tech-M. And in that post, I also told you that one of the exhibits in my care was a 900-gallon reef tank with a persistent bryopsis algae problem, and that I was about to use this method to eradicate the bryopsis algae from my tank.
And . . .
Drum roll please. . . . . . . . .
It worked!
Yes, it worked quite well. Before treating the tank with the magnesium supplement (Kent Tech-M), we did the following important steps to prepare:
PREPARATION STEPS
Step 1: performed two 35% water changes to help up the magnesium level to the normal 1,300ppm and to lower the phosphate level;
Step 2: Manually plucked/removed as much bryopsis as possible while the water level was down (during the water change). We did this during both water changes over a period of one week.
Step 3: stormed the tank with a powerhead on a stick to help get as much detritus out of the tank as possible. We have 4 filter socks in the sump that catch it quite efficiently;
Step 4: Replaced the Rowaphos media (a.k.a. ferric oxide) in our chemical filter (Precision Marine SR55P Professional Series Substrate Reactor), which helps to insult and stress out the bryopsis algae.
Step 5: Began dosing kalkwasser (saturated solution of calcium hydroxide and R.O. water), which precipitates out phosphates so that the protein skimmer can remove them. It also elevates the pH to 8.3-8.5, which helps inhibit the growth of unwanted algae such as bryopsis and hair algae. And kalkwasser also helps to elevate alkalinity, which also helps inhibit unwanted algae.
Step 6: Turned off the activated carbon filter. This is just a hunch, but since the active ingredient in Kent Marine’s Tech-M magnesium supplement is not known (that which eradicates the bryopsis), I certainly didn’t want the activated carbon to remove it. Originally, people felt it was the elevated magnesium level that was doing the work, but after multiple methods of raising the magnesium level produced inconsistent results, it was concluded that Kent Marine’s Tech-M product worked the best because of some mystery active ingredient.
Now that the preparation steps were completed we were ready to begin dosing the Kent Tech-M (magnesium supplement). The main instructions are to make sure that you do not raise the magnesium level by more than 100ppm per day.
So I went ahead with dosing the tank to raise the magnesium level by 100ppm per day until the magnesium level was between 1600-1800ppm, and in one week the bryopsis dropped to less than 50% of what it was before dosing. And by two weeks, 99% of the bryopsis was gone from the display tank. I was quite pleasantly surprised.
Overall it took 2 weeks and the Bryopsis is now gone. It is my feeling that the aggressive manual plucking/removal was a critical step to insulting/stressing the bryopsis. And remember we did this just prior to changing out the Rowaphos media (lowered phosphates to zero) and the subsequent dosing of the magnesium supplement.
We will see what time will tell. I have heard of the bryopsis coming back after a successful treatment, so the constant vigilence will continue – as it always does with a truly successful saltwater aquarium.
Please comment and share your experience with hair algae or bryopsis and how you went about it and what happened.
Tagged with: bryopsis • bryopsis algae control • chemical filter • chemical media reactor • hair algae • kalkwasser • kent tech-m • magnesium • rowaphos
Filed under: Algae control • problem solving
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I tried the magnesium method, and it initially seemed to affect the Bryopsis, but it came back and is now as strong as before.
I read that only Magnesium Chloride works, not Sulphide, so many supplements won’t work. Could it be this rather than a mystery ingredient?
Hello, Andy. The method I described, using Kent Tech-M, is the most consistent and effective method. While other magnesium methods have worked, none have been as consistently successful as using Kent Tech-M. I wish we knew why this is the case, but not one seems to know.
I do know that if you are making your own magnesium supplement, you will need to use both magnesium chloride and magnesium sulfate (otherwise known as epsom salts). However, remember that magnesium chloride, alone, is as effective as with the Kent Tech-M product, which very likely has magnesium chloride in it.
Did the bryopsis came back?
Thanks for the question, Marco. Yes, it has been 4 months since the tank was treated and the bryopsis “disappeared”. The bryopsis has returned, although, this time it is different than before.
What I mean is that when I originally treated the bryopsis, it was a tank-wide outbreak – I mean it was everywhere. And now, when I am treating it a second time, it is only two 1″ tufts about the size of a golf ball. And I am treating it the same way (with Kent Tech-M). So my expectation is that I will be able to knock it back thoroughly and quickly. Stay tuned to see what happens.
@Warren –
The only way to prevent this from coming back is to Stay on top of your water changes. Magnesium is leached from the Live rock over time and has to be replaced, Ideally you would need to do a 20% water change which would be 180 gallons on a 900 gallon tank, this needs to be done every 2 weeks to keep magnesium levels up.
I have 2 210 gallon aquariums and I change water every week, But it never fails, the moment I go 2 or 3 weeks with out water changes and get lazy I end up with Bryopsis again
Thanks, Kirk. That’s an interesting point you make about how sensitive the bryopsis is to suppressed or low Magnesium levels. Now that I think of it, the same thing has happened on my system. Great comment!