Fuge lighting... the final word?

[Smaster121]

My goal with my refuge (now over one year old) is nutrient export primarily to help resolve a perpetual Cyano problem. I recently switched to 24 hour lighting from a reverse light cycle on my fuge hoping that I could get the Calerpa to consume nutrients faster than the cyano and starve it out.

So far not much luck in that department. My phospates and nitrates are undetectable. The calerpa is growing (but not thriving). Yet the cyano blooms profusely.

By the way, I recall reading that the reverse light cycle was intended to level out pH fluctuations that occur when the lights go out. I figure my tank is so unhealthy because of the cyano bloom that the pH problem is a nit.

 

[sjvl51]

Smaster, you are probably getting 0 readings in phosphates and nitrates due to the cyano using them up before you can test for them. This could also be one of the limiting factors in getting your calerpa to grow. The cyano is using up the nutrients before the calerpa has a chance.

What you have to do is reverse the process so that the calerpa is using the nutrients before the cyano. How?? You can increase your lighting. Here is the bulb that I went to - http://www.reefcentral.com/forums/showthread.php?s=&threadid=313318 The difference between 2 NO bulbs and 2 of these was amazing and my macro algae showed a resulting increase in growth. Another limited factor of plant growth is lack of iron. Some people say there is enough iron from regular water changes. I use the Kent Iron and Maganese supplement mentioned here - http://www.advancedaquarist.com/issues/aug2002/chem.htm The last recommendation would be to reduce as much of the cyano as possible to give the calerpa a chance to start using the nutrients first. The fastest growing species will use up the nutrients first so you have to create an excess to kickstart the calerpa. Once the calerpa is in fast growing mode, then the cyano won't have as much, if any nutrients available and will slowly die.

One other comment, growth slows down as the macroalgae becomes crowded. Prune on a regular basis to give it room to grow.

Yes, the reverse light cycle was intended to level out pH fluctuations but I didn't notice any fluctuations to level out. I've tested pH before the lights come on in the morning and at mid day and in the evening and basically get the same reading. This could be due to the inaccuracy of the testing solution or that I top up with kalkwater 24/7. IMO minor pH swings are not critical since they are not sudden swings.

Vickie

 

[sjvl51]

Alanseah, the more light (without burning the algae) in most cases will result in greater macro algae growth. Some people use the MH bulbs that they take off their display tanks.

I found that the macro algae would grow (slowly) with regular florescent bulbs. You would probably get better growth (than regular florescent bulbs) using the plant bulbs that you find at Home Depot or the algae grow bulbs for fresh water aquariums. I use this one - http://www.reefcentral.com/forums/showthread.php?s=&threadid=313318 which is considerably brighter than the florescent bulbs.

Vickie

 

[Smaster121]

I have a LOA outdoor flourescent on the fuge. Running on a 24 hour cycle for one week.

Cyano is blooming gloriously. Calerpa is dieing I expect from too much light. And cyano is blooming because of all those nutrients from the decomposing calerpa.

I'm wondering. Keep to the plan of 24 hour light and hope that the Calerap will regenerate with a more light tolerant generation.

Go back to an alternating cycle with the main tank?

Or something else?

 

[ninjafish]

Smaster,
I don't know the answer either but I think I have decided to go with reverse schedule lighting. I know that many people have had success with 24-hour lighting but I don't know of any macro algae that recieves 24-hour lighting in nature. As unnatural an environment as my system is, the algae has evolved over thousands of years of light and dark cycles and I may as well go with what's worked up till now.
As a bonus it might level out my ph and save a few bucks on electrical costs. JMO.

 

[sjvl51]

Smaster, I doubt if the calerpa is dieing from a lack of light. From what I have seen, the more light the more growth. From what I understand, most calerpa will survive under 24 hour lighting, so that should not be a problem.

One thing to remember, the fastest growing organism will absorb the most nutrients leaving nothing for the other organisms. Your cyano may be using up the nutrients (due to amount of cyano) before your calpera has a chance. You could try reducing the amount of cyano (vacuuming some out) to give your calpera a chance to multiply.

I'm not sure of the spectrum of the light you use. You could change to one of the plant grow tubes that have the spectrum that plants use.

You haven't said which calerpa you are growing. Some do grow faster with a better nutrient export than others.

One other suggestion would be to increase your flow. Cyano does not like high flow and contrary to popular opinion, I found an increase in the calerpa growth when I added a power head to increase the flow in my refuge.

Vickie

 

[mellen]

Smaster- tank is too out of balance to expect Macro to correct the problem with cyannobacteria, so it is dying. Try this; 1)remove any new/delicate corals/inverts or other specimens that you would worry about to short term quarrantine. 2) Buy enough Purigen or Polyfilter to strip your tank after; dosing it with 1 200mg neomyacin or 1 200mg myacin capsule for each 10 gal net volume. 3) turn off skimmer and other physical/chemical filtration for 3 hours (airstones or just powerheads fine. Keep lights ON! Cyanno active/sucking in bactericide). After treatment regimen time, turn on skimmer & use Chemipure and/or Polyfilter inline (filter or strapped to powerhead outflow) to remove dose of bactericide. Your nitrobacter/nitrosomona colonies will be somewhat reduced, so have plenty of fresh, healthy macro (chaeto good choice) to "sop up" ammonia the in-tank colony can't handle yet- recommend 6 to 10oz. Chaeto or other fast non-calcerous algae per 15 gal volume for just this treatment recovery; thin out later over 10 day period. The cyanobacteria will have been at least partially decimated by bactericide enough to allow macro to get ahead in nutrient ad/absorption game, but it must be healthy, FUNCTIONING macro, not your old stuff on it's last legs. Reverse cycle lighting (warmer Kelvin = faster growth) on macro in 'fuge to compensate for O2 production loss during darkness in main display - helps PH/CO2 dynamic to stabilize, too. Recommend you consider adding easy-to-thin calcerous macros like Halimeda sp. to main display as well (they don't "go sexual"). I agree that marine algaes are evolved to deal with and thrive in relatively high volume flow rates. It is, in fact the SAME volume of water going past them with the exact same amount of nutrients to be absorbed in our tiny, closed ecoSCHISMS ...Slow flow in sumps/refugium started out for practical reasons; baffles to catch unsightly microbubbles (which are harmless and natural, by the way!).

 

[mellen]

oh yeah.. use RO and or DI water for WC's. Use only best salt mix - Marine Environment or Bio Assy (sp?)...City water is fine for "peeps", bad for polyps..