Zoanthids/21k Halides and actinics, help please.

[Reefer U.K.]

Hello,
i am hoping to set up a 19"W x 19"H x 25"L cube (with a 6" in tank sump) which will house mainly zoanthids.

However i am unsure about the best lighting option.
I have decided that the 21K Giesemann megachrome blue DE would be a good start (Aidyb uses this bulb to good affect).
My questions are, (a) would i still need to supplement with actinic lighting to get the best effect, or would this not be necessary?, (b), should i go for a 150W or a 250W, given the dimensions of the tank (heat issues etc) and the fact that the tank will hold mainly zoanthids.

Any help or advice would be appreciated,

kind regards,

Peter (from the U.K.)

P.S. if anyone has any good designs for in tank sumps (a bit like the back of a nano cube, but including a skimmer, rowaphos reactor etc but on a bigger scale, it would be great to hear from you, as i don't have a clue where to begin.

 

[Reefer U.K.]

Anyone please!

 

[jessiesgrrl]

Hi, there!

First of all, welcome !

I would try to set this same post question in the nano forum here on reef central. I think the reason you may not be getting much of a response in this forum is because most of the reefers in this forum have tanks larger than that, which gives them a sort of personal experience that is iffy to generalize to a smaller tank. The nano reefers are very well versed in the possible solutions to heat versus water volume in lighting situations. They also have many DIY projects that I find wildly interesting when I read their forum posts, that we would never be able to do on larger tanks.

Also where I might use metal halides on my 55 long and 56 column, on your tank there would be some worry about too fierce penetration of the lights on your corals. Light does not punch all the way to the bottom of most larger tanks, so the intensity and spectrum of our lights must be different/stronger in order to reach bottom dwellers such as zoas. In your tank, there is less depth and therefore more direct penetration of the light. Simply said, smaller/less deep tanks do not necessarily need MH to get much the same results as larger tanks using MH do.

You might also send a PM to Shultz on Zoa-Club.com, as he is also in the U.K. and might be more familiar than we are with UK brands that you could find locally given the differences between what is sold here with American voltage requirements versus UK voltage (220 volts are only used in on country versus the other). Whew, what a run on sentance! LOL

Actinic light is mainly used imo to make the zoas glow more intensely, or to encourage them to open when new to the tank. I've seen some who also think they mimic the moon for a moonlit photoperiod, but honestly I am not so sure what I really think of that idea scientifically because moonlight does not share the same spectrum or effect as actinics, although blue.

Given your tank, I would likely go with a non MH bulb because of too strong light, rate of evap, electricity usage, and heat worries (even with a fan). Something in the 15-21k range sounds much more reasonable for a tank that size because of its cost to benefit ratio.


Good luck and hope to see you here again soon
Laurie

 

[Reefer U.K.]

Hello Laurie,
thanks for the welcome and the advice, i will do as you suggest and post the question in the nano section,

kind regards,

Peter.

 

[jessiesgrrl]

No problem, hun, anytime.

Nice to meet you

Laurie