I have Grape Vine macroalgae in my hang-on Refugium.
Right now the lights are on at the same time as the main display tank.
Would it be better to have the lights on 24/7 or have them on during the night when the main display lights are off?

Thanks for any suggestions

Michael
MAXreefer

a lot of reefers keep the fuge lighting on a reverse light cycle from the DT, to reduce PH swings at night.

What are you growing in your fuge?

Right now I am curing rock in my tank so my fuge light is on 24/7. Once I complete the cure I will be putting it on a reverce cycle to the main tank. As stated before this is to help with pH swings.

Right now I just have some mud, LR rubble and the Grape Vine in there

Michael

Sounds like grape calurpa. If so, you'll want to keep the lights on 24/7 to hopefully keep it from "going sexual" and attempting to spawn.

Sounds like grape calurpa. If so, you'll want to keep the lights on 24/7 to hopefully keep it from "going sexual" and attempting to spawn.

Would you suggest to get rid of it and use another kind?

Michael

Well, yeah, I would. Lots of people use it without issue, but for me, better safe than sorry. Calurpa has many drawbacks. As stated previously, it can atempt to spawn and foul your water, it's very invasive. Let a little get into your display, and you never get rid if it entirely. Also, when pruned, it can release some mild toxins into the water.

If it were me, I'd get it out as best you can and start using some cheato. Then you can run your fuge light on a reverse light cycle, and get some benefit to your pH stability as well as nutrient export from the algae.

I personally use both caulerpa and cheato in separate area of my fuge. I keep it lit 24/7 and prune the caulerpa regularly and have never had a problem with it going sexual. That doesn't mean I couldn't have a problem tomorrow but I think the lighting and pruning vastly limit the chances. I think that caulerpa grows faster than cheato.

I wouldnt suggest changing it unless you want to I've run caulerpa (both saw and grapevine in laymans terms) in both 24 hour and 16 on 8 off cycles without it going sexual. Most people associate it going sexual when lights off when it's really a genetic response to lack of nutrients. This is magnified by the lack of light for photosynthesis and thus the response occurrs. Having had it go sexual in a number of experiments I havent had any real bad problems with that either other than a green cloud to the water temporarily and lots of happy zooplankton.

Running the lights reverse in the fuge to level PH works due to the increased carbon dioxide usage of the macroalgaes during photosynthesis. This can be helpful or moot point dependant on water volume and amount of macro. If your running a handful of macro in a 400 gallon system I wouldnt much worry as the co2 uptake of the macro is probably nowhere near enough to make the slightest difference. if your running a good amount of macro though this can be a signifigant help. All the same, it's always easier to go by the rule of thumb regardless of whether or not you think you have enough macro or not. rather than guess might as well go with it.

Long story short if your seriously scared of a sexual event run 24/7, otherwise most macro's prefer a 16 on 8 off cycle and low kelvin lighting (4100k on down) adjust to fit YOUR needs and on to the next project eh!

Thank you guys for all your valuable input.
I think maybe the safest thing to do is just running plain "chaeto" but at the other end if I keep a good light cycle and prune it regularly there is nothing against running the "Grape Vine" either.

Michael

exactly,

most people argue against caulerpa due to having "read" it goes sexual. While the fact is true should you're upkeep be in check any method will work. Chaetomorpha tends to be a lower maintenance macro to run hence the preferred. Interesting to note however that several caulerpa species are illegal for sale in the state of california, you can have them in your tank, you just cant sell or hand it out as it's considered a nuisance plant. It's amazing the higher growth rate caulerpa is capable of for sure. I had read a study somewhere on the nutrient uptake of different macro's, maybe I'll dig that up again for re-reading here.