How much light?

[Aquadiva]

Well, OK...after about a year of trying off and on, I can't seem to get a good answer to this question:

What is meant by low light, med light, and high light?
Also, low flow, med flow and high flow?

Most of the web pages listing livestock recommend parameters that state something like:

High light, medium flow, excellent water parameters (duh).

OK, so for a 24 inch tall tank (ie a 75) what would High Light be? A 400 watt MH with the coral 4 inches under water, or maybe a 175 MH would be sufficient? What do you guys use as a reference point?

Same deal for flow....do you blast it with a MJ1200 or block it with a rock? Flow, I know, can be extremely hard to figure, but what about light?

Thanks

 

[jango]

with the light I believe that is where the coral resides in nature so you would want to place it accordingly in your tank high light = top,low light = bottom. As for the flow i believe it is the same idea, but you do not want a maxi 1200 blasting the flesh off your coral (it will) you want a broad flow not jet's of water...

 

[Ray]

Good question....in my 75 there was NO low light area unless I made one because I had over 1000 watts on it

 

[Aquadiva]

Jango, I understand what you are saying, but use this example:

Two people buy the elusive Acopora Expensive
Needs described as HIGH LIGHT

Tank 1:

24 inches deep
175MH with VHO Actinic supplimenation
Where does the coral get placed?

Tank 2:

30 inches deep
440 VHO
Is this enough?

There are unlimited number of scenarios for depth, light intensity, etc.
Would a low light coral, (like ray said) be kept in a 24 inch tank with 250 MHs at all?
Looking for some kinda benchmark before I kill a few corals and buy something that will look brown until I get bigger (ie brighter) lights.

 

[jango]

IMO flow and water quality contribute to color as much as light, have you ever seen Greg Hiller's set up some of his corals are under 400w of halide in one tank and the same coral under vho in another both with great color just different...

for example I got one of Greg's pink milli's(miili/prostrata?) that was inches under a 400w halide I brought it home and put right under a 175w halide with no color loss...

 

[Tstone]

In Tank 1 You would place the coral up high. That tank would be considered med light. Here it would be happy but not ecstatic.

Tank 2 would be low light and not enough really for that SPS species. It would survive but not thrive.

High light in the 75 g would be a pair of 250 or 400 watt. 175-150 would be med and then fluorescents would fall in the low to med range T-5 being closer to med.

With that said there are a lot of variables. Shallow tank (12 inch) with T-5 would be high light.


This is my opinion not to be construed as real science

Do as search at RC for articles by Sanjay joshi. You will get some better info.

 

[jango]

if you are buying a coral at a store find out what light's they keep them under and judge from there.

 

[jango]

good to see you lurking marvin...

 

[Aquadiva]

OK, now we are getting somewhere...

Jango...

I was thinking more about the internet...ie live aquaria...it is one of the places I check when looking for basic info on fish/corals, etc. Gives you a rough idea what the animal needs before looking at more in-depth stuff. Pretty quick and easy.

Marvin,

So what you are saying is there is no area of a 75 with 175 MH over it that is considered HIGH Light...medium light at most. I would assume that low light, for stuff like mushrooms and such would be towards the middle bottom. Yes??

Now, Would a 75 with 400W MH over it have any areas that would be considered low light? (Beside the obvious areas that would be shaded)? Sorry for being a pain, but I think I've asked this in two different threads on RC and never got this far.

Thanks

 

[Tstone]

I would say that based on your scenario-75g w/175MH- that up close to the light source would be high light, but that area would be limited as you move further away from the source the intensity would drop rather quickly.

With 250 or 400 that area of high intensity is larger and even at the bottom of the tank without shade would be no less than med light.

Jango I am bustin out.

 

[jackie]

Yeah, I always wondered about that. My tank is 18" high and I'm using 2 175W MH XM SE. I have to keep the SPS I have waaayyy at the top. I've since had a piece of tempered glass made to fit into the light hood and brought the light down so that it sits abouit 1" above the tank. PIA though when you want to work inside the tank.....and the salt spray needs to be cleaned often.

 

[Aquadiva]

Hey guys....thanks..

This sheds a lot of light on the situation...

Linda