Is it possible Mg plays a larger role in GHA than we think?

[tatmanfish]

I'll preface by saying this is purely anecdotal, but could low Mg be the main factor behind phosphates and nitrates or possibly the top culprit?

I've read a few post on here that have said similar, but mostly similar anecdotal evidence. I recently started by 180g build with mostly dry rock. All my previous tanks were 100% live rock back when live rock was readily available everywhere. I dealt with most all algae types, but not to the extent we see today with dry rock.

I just went through the worst outbreak of GHA ive ever experienced. My phosphates tested low( .02-.08) before the outbreak and nitrates were 12-16. Mg was testing on the low end of acceptable at 1220. After several attempts at manual removal, a couple extra urchins, reducing light period, reducing white lighting and intesity, water changes, running a refugium since the tank finished cycling and watching continue to get worse.... I decided to give the elevated MGg a shot and the results have been phenomenal for me. I've been running at 1425-1450 Mg since.

Within days it was reduced to a fraction of what it was and is continuing to dwindle. My CUC is actually showing sign of having an effect on the remaining patches, and I'm seeing almost zero spots of new growth anywhere. I wish some one smarter with far more resources could look into a little more and see if there more of a correlation than we currently understand.

 

[Wrassenaround]

Definitely going to follow along on this one. I have always had success with Algae Barn's Oceanmagik when fighting algae and GHA to be specific. My Mg levels have been low these last few months and the algae is fighting a good war this time.
What Mg did you dose?

 

[Cichlid Dad]

I'll preface by saying this is purely anecdotal, but could low Mg be the main factor behind phosphates and nitrates or possibly the top culprit?

I've read a few post on here that have said similar, but mostly similar anecdotal evidence. I recently started by 180g build with mostly dry rock. All my previous tanks were 100% live rock back when live rock was readily available everywhere. I dealt with most all algae types, but not to the extent we see today with dry rock.

I just went through the worst outbreak of GHA ive ever experienced. My phosphates tested low( .02-.08) before the outbreak and nitrates were 12-16. Mg was testing on the low end of acceptable at 1220. After several attempts at manual removal, a couple extra urchins, reducing light period, reducing white lighting and intesity, water changes, running a refugium since the tank finished cycling and watching continue to get worse.... I decided to give the elevated MGg a shot and the results have been phenomenal for me. I've been running at 1425-1450 Mg since.

Within days it was reduced to a fraction of what it was and is continuing to dwindle. My CUC is actually showing sign of having an effect on the remaining patches, and I'm seeing almost zero spots of new growth anywhere. I wish some one smarter with far more resources could look into a little more and see if there more of a correlation than we currently understand.

Hmmm...... Well I have started with dry rocks in the past. Always had to battle gha. I also was wet behind the ears and new nothing about the big 3. Fast forward. I just started a new tank with dry rock Tampa bay live sand in the display and live rock in the sump. I added my coral in maybe day 2 or 3. My hammers, sticks zoa , Monty's never skipped a beat. No hair algae none of the ugly I expected. I chalked it up to the live sand and rock. It's a 75 gallon with 20 pounds crush coral on the bottom then 20 pounds TDSW live sand on top. Maybe 50 pounds bleached dry rocks. Then 20 pounds live rock in a 40 breeder refugium sump. But I now keep my parameters steady at 450 cal, 1450 mag and 9 alk. You may have a point.

 

[tatmanfish]

Definitely going to follow along on this one. I have always had success with Algae Barn's Oceanmagik when fighting algae and GHA to be specific. My Mg levels have been low these last few months and the algae is fighting a good war this time.
What Mg did you dose?

I run the triton method so I used there's this time. I've used brightwell in past tanks, but not for this particular reason. I also dose phyto.

 

[tatmanfish]

Hmmm...... Well I have started with dry rocks in the past. Always had to battle gha. I also was wet behind the ears and new nothing about the big 3. Fast forward. I just started a new tank with dry rock Tampa bay live sand in the display and live rock in the sump. I added my coral in maybe day 2 or 3. My hammers, sticks zoa , Monty's never skipped a beat. No hair algae none of the ugly I expected. I chalked it up to the live sand and rock. It's a 75 gallon with 20 pounds crush coral on the bottom then 20 pounds TDSW live sand on top. Maybe 50 pounds bleached dry rocks. Then 2 pounds live rock in a 40 breeder refugium sump. But I now keep my parameters steady at 450 cal, 1450 mag and 9 alk. You may have a point.

I believe the established rock has always made it harder for nuisance algae to really take hold without severely less than ideal water parameters. I've honestly never had a hard battle with any algae with some poorly managed nitrate and phosphate numbers on past tanks until this one with dry rock. I may be dating my self, but dry rock mostly went unsold in a tiny box in the corner of most stores while there was a giant tub of tonga, Fiji, ect that was shipped in every few weeks the last time I started a large tank. Lol

 

[Cichlid Dad]

I believe the established rock has always made it harder for nuisance algae to really take hold without severely less than ideal water parameters. I've honestly never had a hard battle with any algae with some poorly managed nitrate and phosphate numbers on past tanks until this one with dry rock. I may be dating my self, but dry rock mostly went unsold in a tiny box in the corner of most stores while there was a giant tub of tonga, Fiji, ect that was shipped in every few weeks the last time I started a large tank. Lol

I wish I knew the good old days