[dupont24]

In the thread what is a good clam to start with, Neo said measuring "watts per gallon is a pretty old way to determine lighting." What is the new way? When we finally set up a 125 I want to be able to keep clams, and we're ending up with 5 watts per gallon w/ VHO & PC (I'm not sure that is enough) There is a better way to figure this out?

Thanks
Robin

 

[Rook]

The important measure is intensity. In order of intensity per watt, and thus amount of usefull light to penetrate at x dept in the water, MH is by far the best, t-5 arguably second, then PC, VHP and NO.

Intensity is not strengthened by increasing number of watts alone. For example. A 55 watt power compact bulb only has a limited amount of intensity, which thus only reaches a certain depth. Adding a second 55 watt bulb would not increase the intensity and would not increase the depth that the bulb breached. BUT, switching to a 110 watt PC bulb would give more intensity and depth! Also, 55 watts PC does not equal the intensity of 55 watts MH.

That in a very rough idea is why watts per gallon is inadequate. You could have 10 55 watt PC's and be no where near the intensity of two 250 watt MH.

 

[dupont24]

What is t-5? I haven't heard of that before. And can you recommened a book or site I might find more info on this? I know MH is the best but I don't think we'll have enough room. I may need to think about a custom canopy. I get what your saying about intensity & depth, we had a 45gal corner that is very deep and had problems with getting the light to the bottom.

 

[Guest]

Light is measured using a few methods.

Lux is equal to 1 lumen per square meter. I believe it is also refered to as the amount of light of one candle at one meter in terms of luminesence. This is an actual measure of intensity. They sell LUX meters that are some what affordable and will give a pretty acurate reading. The average irradiance over a reef is 75,000 lux (taken from Aquarium Corals). I am not sure if any bulb in the hobby gets that high in terms of intensity.

PAR Photosythetic Active Radiation The amount of Radiation and or Light Energy that is theoretically available to a photosythetic organism.

PUR Photosythetic Usable Radiation. The asmount of Par that is available for use by a photosysthetic animal.


In terms of PAR The Lower the color temp the higher the PAR is a rule of sorts. I use 20K bulbs so I have a lower PAR going into the water. I compensate for this by using a higher wattage to punch the light to the bottom. DO not be confused though. Wattage is not actually a measure of intensity or the amount of light that will reach a coral.

An Example

2-110 watt VHO vs 1- 175 watt MH

The MH bulb is a point source of light. All the intensity is generated by the filament in the center of the bulb and from there is is directed into the water. It is more intense D/T concentration of energy and will penetrate deeper into the water for the same reason.

A Flourescent tube of the same or higher wattage spreads its light over several feet. SO it will not penetrate as deep and therby is not as intense.

A simple way to demonstrate this is to take a flashlight and shine it in your tank at night. If you have a mag light you know its adjustable in terms of beam. A wide beam will light a wider area but it will be dimmer. A narrow beam will not light as much area but you will be able to see all the way down.

I think thats the best way to explain the differce The wattage never changed per se' but the intensity did based on delivery.

 

[dupont24]

Ok, now I have a better idea of what's going on. But I still will be reading more on this. Thanks

 

[Guest]

I would always say to take everyones opinion and then read and read and form your own on the subject. All the lighting methods have pro's and cons. I like MH because I prefer more photo intenseive corals. I like the glitter lines becuase it looks natural in the reef.

I like PC's and VHO though because I think they are great for mushroomsand softies. It boils down to what you wnt to do in th tank really and what you believe is best for your set up.

 

[dupont24]

When we set up the 125 I want to be able to have clams, which I understand need the highest lighting requirements. The canopy that we picked out will not fit m/h, so i'm thinking that we need to look into building our own. I like the color spectrum of VHO over PC. So I'm thinking that we may need to do a combination of M/H & VHO. But I want to read more on the subject.
By the way we took your advice and are looking on ebay & the RC selling forums. they do have some really great deals, but it may be longer than planed, before we have a full set up. Being as we are going to have to do this piece by piece instead of getting the whole set up at once.

 

[Guest]

were you guys at the Swap?

 

[ofblong]

from what i have seen it takes more t-5 bulbs to equal the same light as 1 pc bulb

 

[Guest]

I think though that the T5 is supposed to be more intense. Thats what I am reading right now. Who knows..They are still fairly new to me.

 

[dupont24]

no we couldn't make it to the swap but if the tank tours happen we'll be there!

I guess my problem is that I want it all! I want to be very diversifed in what we have in the tank LPS/SPS, mushrooms, clams etc. At the rate I'm going I'm going to need either 2 tanks or a REALLY BIG one. LOL

 

[nbd13]

if you want SPS and clams like cocera or maximas, go with MH, it would be hard to get growth out of SPS and clams in a 125 with VHO, i am getting growth out of SPS and i haev a 70 gallon with 660 watts of VHOs. i guess i am lucky, knock on wood it continues, but who knows.

Nick

 

[Guest]

The MH at 250 watts with lots of VHO would be nice for a mixed reef like you are thinking of. PM and we can talk more about it when you get ready.

 

[Nautal]

quote

Originally posted by dupont24

What is t-5? I haven't heard of that before. And can you recommened a book or site I might find more info on this? I know MH is the best but I don't think we'll have enough room. I may need to think about a custom canopy. I get what your saying about intensity & depth, we had a 45gal corner that is very deep and had problems with getting the light to the bottom.

</blockquote id="quote">

 

[Skippy_electrician]

OK, im fairly new 2 reefkeeping and lighting requirements, but I know a fair amount about lighting in general and lamps (which are pc and such) and bulbs (MH). Simply a t-5 is a lamp that is 5/8 inch in dia. The standard bulb that u see in stores and schools or office buildings are generally T-12. Meaning it is 1 1/2 in dia. For every 1 (T-5 being 5) there is 1/8th inch dia. So a *-8 is 1 inch in dia and a T-5 is 5/8 inch dia. T-5 are fairly new but all they really are is a more slimline lamp. As stated abouve a T-12 or T-8 lamp will have no more intense light than a T-5. )