Chaetomorpha Algae Not Growing

Resvordog · Jul 28, 2015

Hi everyone,

I was wondering if anybody had any ideas on why the Chaetomorpha algae in my refugium is not growing. About a year ago, it was growing so well I could hardly keep it under control. Then one time I trimmed it back using a pair of scissors like I had done many times before and it not only stopped growing, but started dying back. Eventually, there was none left. I thought it could have been the way I trimmed it back, but I purchased a few more healthy bunches and they died too. I have a Marineland "reef capable" LED fixture on the refugium. I thought maybe the algae wasn't growing because it needed more light, but that would not make sense considering it did so well before. And it couldn't have been that there were not enough fertilizers (nitrates and phosphates) in the water because I have several big fish in my display tank. I test for nitrates and phosphates every couple of weeks. Before I traded out my Naso tang because he got too big, my nitrates were running at about 30 ppm and my phosphates between 0.2-0.5 ppm. After I traded my Naso out 6 weeks ago, my nitrates are 5 ppm and my phosphates are 0 ppm.

My other levels are as follows:
Salinity-35 ppt (1.026 SG)
Magnesium: 1350-1390 ppm
Calcium: 450 ppm
Alkalinity: 9.8-11.2 dKH
Iodate/Iodide: 0.04-0.06 ppm (hard to tell most of the time)
Iron: 0.04-0.07 ppm
pH: 7.95 (because of calcium reactor)

I supplement my tank with a comprehensive amino acid/trace element supplement, liquid bioavailable carbon (to help bacteria better break down waste), a vitamin C supplement, and coral color increasing supplement. All of my corals and fish are doing great and growing rapidly.

I do wonder about plasticizers being the culprit. I recently read a study on flexible PVC tubing and how plasticizers leach into aquarium water over time, stunting growth of corals and causing other issues with fish and invertebrates. I have silicone tubing being shipped to me and plan to replace all my PVC tubing in the next few weeks.

If anyone sees any issues with what I'm doing with my tank, as far as supplements or general tank parameters, that may be the reason my Chaetomorpha does not grow, I would greatly appreciate the feedback.

Randy Holmes-Farley · Jul 28, 2015

Is iron a listed ingredient in any of your supplements?

Amoo · Jul 28, 2015

tagging to follow

Resvordog · Jul 28, 2015

Randy Holmes-Farley said:
Is iron a listed ingredient in any of your supplements?

Yes. I'm using Seachem Reef Plus and it lists iron as 0.009 mg per gram of the supplement. I'm using Brightwell Aquatics Ferrion to boost the iron, which Brightwell recommends to be between 0.05 and 0.10 ppm in the aquarium.

Randy Holmes-Farley · Jul 28, 2015

OK.

FWIW, an iron supplement can help macroalgae (and I dose it), but don't for a second believe that recommendation on the amount. Natural surface levels of iron in the ocean are more like 0.000006 ppm.

I discuss iron here:
Chemistry And The Aquarium: Iron In A Reef Tank ? Advanced Aquarist | Aquarist Magazine and Blog
Chemistry And The Aquarium: Iron: A Look At Organisms Other Than Macroalgae ? Advanced Aquarist | Aquarist Magazine and Blog

peter fumo · Jul 28, 2015

Would one need to supplement iron if they're running GFO in reactor??

Resvordog · Jul 28, 2015

Yikes! Since iron levels are that low in the ocean, and my other supplement already has iron, then I'll stop dosing iron and see if that helps. Do you test for iron and if yes, what level do you recommend? I don't know of any test for the average reef keeper that can detect such low amounts.

Randy Holmes-Farley · Jul 28, 2015

peter fumo said:
Would one need to supplement iron if they're running GFO in reactor??

I'm not sure, but I do.

Randy Holmes-Farley · Jul 28, 2015

Resvordog said:
Yikes! Since iron levels are that low in the ocean, and my other supplement already has iron, then I'll stop dosing iron and see if that helps. Do you test for iron and if yes, what level do you recommend? I don't know of any test for the average reef keeper that can detect such low amounts.

There isn't. It's not worth measuring iron. Even Triton cannot.

I'm not suggesting less iron will help you, just that you need not aim for that high of a target.

mfinn · Jul 28, 2015

One thing that really helped increase chaeto growth in my refugium is when I added a powerhead to move the water around.
The first one I tried ( worked ok) was a maxi-jet 1200, but I would have to unclog it frequently.
I now use a tunze 6045 that doesn't clog as fast.

Resvordog · Jul 31, 2015

mfinn said:
One thing that really helped increase chaeto growth in my refugium is when I added a powerhead to move the water around.
The first one I tried ( worked ok) was a maxi-jet 1200, but I would have to unclog it frequently.
I now use a tunze 6045 that doesn't clog as fast.

I added a maxijet either 900 or 1200 (can't remember which) a long time ago because I read chaeto likes high flow, but that hasn't helped either. It just gets clogged with bits of chaeto that fragment constantly.

I'm not worried about plasticizers from vinyl tubing anymore. I talked to a family friend who has a PhD in petrochemical engineering and he said it's very unlikely that plasticizers would leach out of the tubing. They are very stable molecules, and the quantities used to make PVC tubing flexible are so small that they wouldn't cause any harm even if they did leach out. The reason vinyl tubing becomes rigid after a while is because it is likely absorbing saltwater, whose salt molecules, metals, and trace elements crytalize between the vinyl molecules and form an almost impenetrable casing inside the tubing. He also said that if plasticizers were a real threat to aquatic life, then vinyl tubing sure as heck would not be used in so many different things humans are in contact with, like medical devices and machines, soda fountains in restaurants, and potable water lines in homes. In case you interested lol