How much lighting?

[richardhmc]

I have a 50 gallon wide tank with a outer orbit lighting fixture over it.
Two 96W actinic power compacts and a 150w MH so 342 watts of lighting all together. That's alot of lighting and thats one of the reasons why green algae keeps appearing in my tank. My parameters are fine so I believe it is the lighting. I used to have algae before and after it was all gone I left the lights on for ONE day. The next day (today), the algae is all back. I have a zooanthid as the only coral in the tank so I need the light as well. So how much lightning should I have in order keep the coral healthy but prevent algae spikes? Thanks!

This is my light
http://www.marinedepot.com/36_inch_..._USA-CU01040-FILTFIMHMPMDMLM5-CU01041-vi.html

 

[Avi]

richard...what are the actual dimensions of your tank?

 

[richardhmc]

36 x 18 x 18 - why?

 

[Avi]

Because the length of your tank is relevant to the metal halide lighting over it....A bulb of the kind you have has a lighting breadth of just about 24-inches so there is that to consider as to the sufficiency of your lighting for corals that aren't under that 24-inch span. But, anyway, I think that you'd be better off using a 4-bulb T5 fixture that has individual reflectors for each of the bulbs.

 

[mr_X]

a t-5 fixture is not the answer to algae issues.
i think you'd be better off upping your nutrient export.
you see, the algae is blooming when the intense light and nutrient rich water makes for a perfect situation for growth.
you need to do some regular water changes with good source water (R.O.D.I.), and cut back on feeding.
in time you won't see it.

as far as the zoa is concerned, they will live under almost any light. you don't need a MH fixture in order to keep them.

 

[Avi]

I didn't suggest that T5s are some kind of magical answer to algae issues but it would reduce the lighting by about half and have sufficient lighting for richard's coral and at the same time have a better spread of light over his tank. richard mentioned that his water quality if good so unless you don't believe him, I'll stick by the T5 recommendation for his tank.

 

[richardhmc]

I do regular water changes every two days, and I use a good RODI.
The lighting is definitely the main factor of the algae. I'm hoping to put this to good use though instead of just buying another new light. Are T-5s a better option than MH/PC?

 

[mr_X]

okey....buy a new fixture then.

 

[mr_X]

btw, i'll take that junky old algae machine you have over your tank now if you don't want it.

 

[Avi]

Are T-5s a better option than MH/PC?

T5s are an option, not necessarily a better option. It depends on a lot of factors like the size of the tank, the kind of coral you keep, just to mention a couple. I have a combination of MH and T5s on my reef but it's 120-gallons and I have SPS, LPS and soft coral so these are different factors that go into my choice for my tank. But, your tank is only 18-inches deep and you aren't keeping SPS so I would say that in your case, with the flexibility of the kinds of bulbs that are available in T5s and the size of your tank...it would be the best option for you. That's just my opinion, so listen to others to before you make a decision.

 

[richardhmc]

I plan to keep LPS, Soft, and SPS corals. I like this sort of lighting its just that I need to know how much I should keep them on for

 

[Avi]

You mean you like the lighting that you have now. First you should recognize that you do have a huge amount of lighting on the tank. But, if you'd want to keep it at that intensity then I'd suggest you keep the MH bulb on for no more than 4.5 to 5 hours a day. See if that works for you. Time would tell. But, you could certainly keep those kinds of corals with the T5s as well.

 

[jackson6745]

Light has nothing to do with your algae problems. You can't hide your tank from light. Your problems stem from nutrient levels. You should try running some phosban. Looking into cutting out the source of your phosphate or at least reducing it.

BTW regular testkits are useless for testing phosphate.

 

[richardhmc]

I cut down the lighting from 6 hrs of MH and 5 hrs of PC to 4 hrs of MH and 6 hrs of PC.
I was told I should leave the PC on for longer than the MH so hopefully this will curb the algae.


If it doesn't work I think I'll buy some phosphate remover to help with the algae problems. I don't use a regular testkit - I use a special Reef intended test kit by API.

 

[cali_reef]

I do regular water changes every two days, and I use a good RODI.
The lighting is definitely the main factor of the algae. I'm hoping to put this to good use though instead of just buying another new light. Are T-5s a better option than MH/PC?

You do a 5%+ water change every 2 days?? :bigeyes:

Algae needs more than just light to grow.. I am sure Algae can grown just as good with T5's given the same water conditions exist.

<--- Algae growing expert.. :lol2: