Metal halide-Penetration

[daddy01]

Hi,
I have a small Reef type tank with a combination of Bubble corla, Frogspawn, Anenome and clown fish, Damsel and shrimp. I have a 150W Metal Halide 20K DE fixture. What is the penatration of the 150W Metal Halide my tank in 21" high but with 2" Argonite sand.
Jim

[mseepman]

Normally, I would say that 150W MH is fine for about 19" of depth that you are mentioning. While using a 20k bulb, you will obviously see less light penetration than when using a 10k.
I too have a 150W but my tank is 24" deep and it doesn't do enough, even with a 10k bulb.

[Doug]

I often wonder how we arrive at all the lighting conclusions. This is just my opinion of course.

150,s are not bright enough for anything but small tanks. However, the local store has one of the 150 HQI units over a 180. Its a 3 banger & I can tell you its brighter to my eye, than my T-5,s, brighter then my 400w radiums on pulse starts & certainly brighter than my 12K 250w on a normal ballast. They are 10K by the way.

So, like some say, are my eyes decieving me? Mark, why dont you think the 10K is enough penatration? Is it a lot dimmer towards the bottom?

By the way, I have read all the par values on these bulbs and see the smaller readings for the 150,s but.........

I think Jim, has enough light for his aquarium. We have a 16in. deep tank at the store with a 150 HQI high overhead and it still looks good at the bottom.

[kwirky]

sanjay's lighting info gives the geisseman 13k mega marine a par of 92 on an HQI ballast. the XM DE gets 60. That beats out a 250W 13k like the aquaconnect (62 par on an 250W hqi ballast).

When my bulb needs to be changed I'm switching to the geisseman mega marine. I had one before in a DIY HQI light and it was frickin' bright.

[mseepman]

My thoughts on my 150 not being bright enough stem from a few different things, including observations on corals put at the bottom of the tank.

First off, the general consensus on RC, here and RAG all seem to agree that 150 HQI is still not meant for deep tanks. Secondly, if I put a clam on the bottom of my tank (I have about 1" of sand) it will die in a relatively short period of time. If I move it up, it can thrive. Any coral that has required a reasonable amount of light has been unsuccessful if I put it near the bottom of my tank.

I have run the original Coralife 10k, Coralife 14k, a Sun-blaze 14k, and now will be switching to a new Ushio 10k this weekend.

So far, these are just my observations with my own tank.

[Doug]

Originally Posted by mseepman

My thoughts on my 150 not being bright enough stem from a few different things, including observations on corals put at the bottom of the tank.

First off, the general consensus on RC, here and RAG all seem to agree that 150 HQI is still not meant for deep tanks. Secondly, if I put a clam on the bottom of my tank (I have about 1" of sand) it will die in a relatively short period of time. If I move it up, it can thrive. Any coral that has required a reasonable amount of light has been unsuccessful if I put it near the bottom of my tank.

I have run the original Coralife 10k, Coralife 14k, a Sun-blaze 14k, and now will be switching to a new Ushio 10k this weekend.

So far, these are just my observations with my own tank.

Interesting observations. I agree about Sean making a good point though.

[Jason McK]

Originally Posted by kwirky

sanjay's lighting info gives the geisseman 13k mega marine a par of 92 on an HQI ballast. the XM DE gets 60. That beats out a 250W 13k like the aquaconnect (62 par on an 250W hqi ballast).

When my bulb needs to be changed I'm switching to the geisseman mega marine. I had one before in a DIY HQI light and it was frickin' bright.

Very good point Sean. It is more the combo if Ballast and bulb that will give you the light out put or PAR. It's important to know that some bulbs just won't perform well with a particular bulb. the example above is a great one

J

[Snappy]

All else a side I'm not sure why you are concerned about it with the livestock you have. Other than the anemone which will move up higher on it's own if it wants more light, there isn't anything you mentioned that needs any real intensity. Are you thinking for future reference? IMO if you are only keeping softies and/or LPS that light should be satisfactory.

[daddy01]

here is a picture of my tank with the 150W metal Halide.
Attachment 2434