Refugiums - Getting One Started

[botsman]

I recently upgraded to a refugium in my sump. Although I have many types of algae growing in my main tank, I have had problems keeping a culture alive in the refugium. I have halides in the main tank but T5's in the refugium and I keep the lighting for the refugium on 24/7.

I think that I should switch to a day/night lighting system in the refugium but the people that I deal with at the shop tell me that this adds risk of a crash and that they have success with 24/7 lighting.

I am aware of osmotic effect and acclimate any algae cultures thoroughly - yet no positive results. Any suggestions?

 

[SkiFletch]

Yeah, ditch any Culerpa species you have (they're the ones that can go "sexual" on alternating periods) and switch to Chaetomorpha (no risk to your tank). Then when its only chaeto in there, use an alternating light cycle. Thats what I do and it works great

 

[botsman]

Yeah, ditch any Culerpa species you have (they're the ones that can go "sexual" on alternating periods) and switch to Chaetomorpha (no risk to your tank). Then when its only chaeto in there, use an alternating light cycle. Thats what I do and it works great

Okay, but shouldn't my caulerpa have been thriving anyway as I pre-empted the sexual cycle by lighting continuously?

I did not know that Chaetomorpha do not pose the same risks re: sexual reproduction and subsequent death/crash and I will switch. In the meantime should I worry is that I am having a die-off within my refugium that I can't explain?

How risky is caulerpa with an alternating lighting cycle? I have a skimmer so I am not too worried about the organic matter associated with plant death and as for more nitrates, my levels are zero. One more water change won't kill me, or am I being naive?

 

[SkiFletch]

Okay, but shouldn't my caulerpa have been thriving anyway as I pre-empted the sexual cycle by lighting continuously?

Because 24/7 lighting is cheating biology. In order for plants/algaes to function properly they must stop photsynthesizing at some point and fix the energy they gained through photosynthesis into carbohydrate energy (by absorbing CO2). Usually fixation occurs at night. Sometimes plants can adjust to a 24/7 light cycle and turn off photosynthesis and turn on fixation, but sometimes they cannot. I'm not sure if its different with each species of culerpa or what, but there are lots of mixed reports on the success/failure of the 24/7 scheme.

I did not know that Chaetomorpha do not pose the same risks re: sexual reproduction and subsequent death/crash and I will switch. In the meantime should I worry is that I am having a die-off within my refugium that I can't explain?

I wouldnt. Your algaes are probably so nutrient deprived at this point that they dont have enough energy to "go sexual"

How risky is caulerpa with an alternating lighting cycle? I have a skimmer so I am not too worried about the organic matter associated with plant death and as for more nitrates, my levels are zero. One more water change won't kill me, or am I being naive?

Its hard to quantify the risk, especially without knowing lots and lots of details about your tank. The way I've always approached the issue is why risk it when chaeto does the same job with no risk and gives you the ability to pH balance with an off-set light timing? Chaeto is cheap and easy to come by, just ask most any established reefer and they'll be happy to donate. So the risk (wich may or may not be substantial) outweighs the reward (minor inconvenience to find someone with chaeto) IMO.

One last question, what color temp T5 lights do you have on the refugium?

 

[botsman]

1 x 10000 K 8W and 1 x 8W actinic. I wonder if I need the actinic?

Thank you very much for your advice and information. Although the hobby is far from new to me, forums discussing it are and I appreciate your concise and informative responses.

 

[SkiFletch]

Glad I could help. If I were you I'd actually dump that actinic bulb and go for something like a 6700k designed for freshwater plant growth. Most macroalgae species naturally live in shallow waters where those higher wavelengths are still readily availavle and are more adapted to use red light (found in 6700k's) than blue light (10ks and actinics).