Macro Algae dies, nuisance Algae thrives in display

I cannot grow macro algae in my HOB fuge no matter what I try. I know there is not a shortage of nutrients in the water because algae is everywhere in my display tank so much I have to clean every few days and I am getting fed up. I run the light on the fuge for about 10 hours a day and I run the display tank about 6 hours a day. I have tried cheato which stayed the same size for about 5 months then I threw it out, now I have caulerpa and most of it has turned white and died the guy at my lfs said he grows it all day under 10,000K light which I have it under. Its crazy nothing can live in my fuge and it is spotless but my display tank has algae growing all over the place.

I think it may be too much lighting on my display, I currently have a 36” nova current light with 3 bulbs (one actinic one 10,000 and one pink) each of which are 39w. The tank is 29 gallons so I adjusted the legs on the light to fit but the tank is only 30”. I have green hair algae all over the glass and now starting on the rocks. The only place it isn’t growing is on the glass that the rocks cover up out of the light. I just replaced the bulbs so I know they are good. I do weekly water changes and I have a skimmer on the tank rated for an 80gallon. The only difference between the barren refugium and display is lighting

I have attached some pics of the algae in the display

 

For my .02, that isn't too much light but maybe the spectrum is off with the pink? I'm not as knowledgeable about lighting spectrum so others can chime in on that. What else do you have in the fuge besides the macro algae? What you are seeing does not make sense.

Have you tested your display tank's parameters - specifically phosphate? I think you can assume you have an abundance. Do you run anything else like GFO or phosguard and/or carbon. Those things might help to bring your levels down in the DT and maybe help keep the nutrients in the fuge. I'm just trying to help......

 

I haven't been able to make it to my LFS this week to test the parameters but I will this weekend and report back. I do have a bag of seachem phosguard in the first part of my fuge and I only use RO/DI water.

Like I said the only difference from the display and the fuge is the lighting and I run the fuge lighting longer. I have also tried 67000K and 10,000k with the same bad results.

 

Hmmm I was going to say the light color, but if you have indeed tried 6,500k with bad results then let's keep at this..

...what is the fuge? You say HOB, does that mean CPR? Aqua fuge 1 or 2? What size? how much sand, how much rock? where the rock and sand alive"? How old is the system, how old is the fuge? what macro algae have you had died?

Whole nine yard on it pretty much

 

I've kinda had the same problems. I've never been able to grow macro algae, but nuisance algae doesn't have a problem! That's one reason why I started using an algae scrubber. It uses the nuisance algae to an advantage. Definitely something worth looking into if having problems with algae, especially hair algae! It keep a the algae on the screen, instead of in your DT

 

Is your refugium light CFL or T5? I have found 6400K CFL bulbs from home depot grow algae like crazy. I had a similar problem when I was using T5's in my refugium and LED's on the display. The LED's were providing a better spectrum than the T5 so the display was out competing the refugium in terms of algae growth. After switching to CFL my refugium is full and the display empty of macro algae.

 

Alrighty, the tank is about a yr old and the refugium in a hob large cpr there is no sand or rubble rock just macro.

Since getting these new bulbs is when ive really seen the increase in algae growth but of course nothing in the refugium its as clean as a whistle.

I am using an old T5 light from my 10 gallon on the fuge.

 

Old bulbs can be a problem as the spectrum is off.

A couple of things that really started making my chaeto grow was flow and going to a 2700k (Soft White) CFL bulb. Macro algae really likes a red spectrum and a 10,000K is way to blue. Also, the macro algae needs a reasonable flow (not nearly as much as your tank, but not stangnant either) for respiration. My growth improved when I increased the flow a little bit through my fuge.

I would start with a new bulb at 2700K and see what that does for you.

 

Based on my experience I would switch the T5 to CFL. I think the light built for those refugiums is CFL, maybe.

 

Switch the bulb to CFL or a low K t5 even.... but if your trying to use calurpa especially you need to run your fuge light 24/7 or it will go asexual (sounds like it already has, by most of it going white.....) and can spread into your DT as well.