Macroalgae Theory and Practice

[DaveV]

Hi all -

I recently received a shipment of chaeto from @AlgaeBarn and gave myself a bit of stress in trying to make sure it survived (past attempts failed). The good news is; it's growing, and as of this morning I've seen my nitrates have dropped from 4ppm to 2ppm so I'm feeling more successful than past attempts. I will say that adding flow helped and an AlgaeBarn blog post about using an air stone for flow seemed to make the difference (thanks!)

Here's just a theory question; if we're maintaining non-zero nitrates and phosphates in our reef aquariums, we're lighting our refugiums on the opposite schedule of the display tank, that means that for something like 10-12 hours a day the display is lit with high intensity lighting with excess nutrients in the water - how do we not get nuisance algae in the display?

I'm guessing the answer is that absent any kind of a clean up crew nuisance algae would be expected to show up in the display, correct? There's no "magic" here that's going to prevent that, is there?

I've also notice GHA growing on the chaeto itself although perhaps less with the flow? Still monitoring that. So far, I've just been picking it out by hand which is a bit time consuming. I'm hoping to eventually get to a place where that's not an issue and the chaeto is pretty hands off except for the occasional harvesting.

Thanks for any thoughts.

 

[Quietman]

So first of all great job on getting your nutrients down with the macro.

Don't spend too much time analyzing time of day variances if you're running a natural nutrient reduction method. I don't measure more than once a week (and since I'm very stable now with my ATS it's once a month).

You will likely get to near 0 (and perhaps 0) nutrients with your macro (instead of non-zero) and that's fine. It's just the algae taking up the nutrients, there are still nutrients being taken up by your corals, just remove some algae or reduce lighting schedule.

Filamentous algae (GHA/turf) will out compete your macro algae as will cyano. Keep removing it manually. It may be part of tank for a long time since that stuff is so good at nutrient uptake. But if it's in your fuge then it's fine really. You'll want to keep removing to keep your macro healthy.

You may have some algae in your display but as long as conditions are better in your fuge most of time then that should be the location where most of it is. I run my ATS on a cycle where the lights are off from 2000 to 0000 and not a full reverse just for that reason.

 

[AlgaeBarn]

@Quietman well said! I would also recommend to remove some of the chaeto before you get to 0 nitrates. Glad to hear our blog helped you!!

 

[DaveV]

@Quietman thanks for the response.

A bit of a story here, but as I was getting my tank set up (about a year ago), AlgaeBarn kind of dried up as a source of clean chaeto. Because of that, I ended up using plastic needlepoint sheets as a surface to grow GHA on down in the sump and that worked great.

In doing that my logic was I think, what you're describing - if GHA is growing in the sump under dedicated lighting in ideal conditions, then all I need to do is remove it from the display and the "replacement" algae should primarily grow in the sump - being the most hospitable location.

Now I switched from the GHA on the plastic sheets to chaeto which I did because cleaning GHA from the sump was a bit of a chore. In that switch to chaeto, my nutrients spiked and now I have a GHA outbreak in the display. Which is to be expected I guess but still disappointing. I was kind of hoping the chaeto would go in and would immediately take the place of the GHA in sucking up excess nutrients - not so much...

Complicating the GHA outbreak is that I'm also treating my fish in a hospital tank for a suspected velvet outbreak so it's probably at least 4 more weeks before I can get a tang back in the display to help with the GHA. Unrelated to algae, but just to complete the story, since I had to catch all my fish I basically tore apart my rock work so my tank went from, "under control and looking good" to, well, a shambles?

I feel like "under control and looking good" is probably at least 3 month away now. Right now, I have just a handful of coral frags and a few inverts living in the display. On the plus side, I'll have time to improve the rock work and figure out coral locations while I wait for my fish.

I'll tell you, I'm half-tempted to go back to the GHA on needlepoint sheets if I'm going to be picking GHA off chaeto from here on out. Or, perhaps, get an algae scrubber which is pretty much what I was doing - just more contained.

Anyway, thanks again.

 

[Quietman]

That's actually the reason I got an ATS. After a dino wipe out of my tank GHA took over. Always had low nutrients from day one, it's just that GHA has the quickest up take of available nutrients. My tank was just a green wavy mess.

I knew macro wouldn't be able to establish itself against that. At least without constant manual removal and really don't have room for a fuge anyway.

So out came my Tunze 9410 DC a skimmer I truly love and in went a RAIN2 ATS from Santa Monica. I saw improvement pretty quick in how the GHA looked. Even then there were setbacks and it took over 2 months for the DT greenery to disappear and wasn't sure it ever would. And yes, lots of manual removal. All in my build thread. So far looking at three weeks with a GHA free DT. Haven't cleaned Jack.

All this is to say...I feel your pain. You're looking at this exactly right with reasonable expectations.

Good luck.

 

[DaveV]

Cool. Thanks for the feedback.

I have to admit, I didn't know 'ATS' until your last reply - I'm going to continue to give the chaeto a chance but an algae scrubber is pretty attractive.

Cheers!