I am fixing to start up a 125g

[kdogg85]

Guys, the mts has got me. I am fixing to start up a 125g. I am going with two islands and was wondering if I could use two 24'' 250w Mh fixtures instead of one full length fixture? The tank has a brace and a sheet of glass in the middle of it. This area will be only sand and each end will be a rock mound. I am going for lps, shrooms, softies, and at the top of each mound, I want to make a clam crown. Would the lights being directly over the top of each mound do the job?

This tank will have a 30g sump, I want to try a turf scrubber, I think a 13x13 screen will do, but what size spraybar should I use?

 

[cmor1701d]

Sounds like a plan,, but that may be too much light for clam. You'd be better off having them on the sand or botom with 250w MH in a 125. My crocea did just fine on the sand bed of my 136 under 150 mh.

Have you considered LED's instead. They may cost more up front but use less electricity and require less top off.

 

[kdogg85]

To be honest, I would not know the first thing about setting up led's. I have read a ton about them, but can't really get a simple breakdown of what's going on. Kinda like the turf scrubber I want to employ. If someone could point me out a simple plan, I would be all for it. Money is somewhat of an issue, but not too bad($650 is my limit). When I seen that the light specs for maxima's and crocea's said high, I assumed this range of output was what was called for. If I could get an led setup for under 650 bucks, I would be flying. I am all for diy too if there are certain guidelines I know to go by.

 

[kdogg85]

Here is a pic of the tank. Around the center brace is a sheet of glass, I think it may be structural and don't want to remove it. I think having a light over top of it would be a waste. I done some more reading on led's, and am still stumped as far as how to determine the output I would need and what parts to buy to make it work. And is there a certain mix ratio of blue's to white's to get a similar look as 12000k t5ho's. That's what I have on my 180g and love the way that looks.

 

[cmor1701d]

I can set my LEDs anywhere from 14k to 24k. I'm set at 20k now and that is 60% white, 100 blue at 100% power. My system does a slow ramp up every 5 minutes for 2 hours to get to 100% and then the same 2 hour ramp down to dusk and then moonlight.

I could set my lights to 14k when I get home and check the white/blue mix for you, but that would only be for the led I am using. Different manufacturers have different outputs.

 

[kdogg85]

Ok, the k value is adjustable. What equipment do I need to look for? Is it just get a panel, lamps, ballast and wire up what you want? And where would I look for lamps and what type of output should I look for, I would like to try a few high-light varieties of corals as well as clams.

Anyone have any suggestions on the turf scrubber? As far as spraybar pipe size goes?

 

[cmor1701d]

I'm not sure which led's my Pacific Sun unit uses (1w model).
I did some tests last night and came up with these numbers

13.1k Whites @ 100% Blues @ 0%
14.0k Whites @ 100% Blues @ 20%
16.0k Whites @ 100% Blues @ 60%
18.0k Whites @ 100% Blues @ 100%
20.0k Whites @ 60% Blues @ 100%

I didn't take it any further, but it can go up to 24k. I'm currently running at 100% power too (started at 50%).

The newer units are using Cree 3w LEDs.

 

[kdogg85]

K value aside. Would say a 120w led fixture be the equivalent of a 250 mh fixture. Or does output stay the same no matter what type of lighting is used. And, does the par value get checked the same way. I keep hearing this is more important than wpg.

 

[cmor1701d]

The PacSun BT-EX (120 x 1w) is supposed to be 400w MH equivalent.
PAR is checked the same way and is less at depth than MH (faster falloff).

So far my new clam seems quite happy (no gaping) sitting on the sand bed.

 

[Ziggy953]

My thinking is that LEDs are still so untested that we don't know for sure how our tanks are going to react and respond. Comparing them to any other form of lighting is futile IMO.

I have seen tanks with LOTs of LEDs over them do well and tanks with minimal LEDs over them do well. I just feel we haven't been using them for this application long enough to really determine how many, what height and what power they need to be to maximize their benefit.

I'm going to be using them for my FW Planted tank. I've just finished my first panel of 1w Crees (24 12 white and 12 blue was gonna be for a reef) I intend to add and additional 12 in 2 more panels bringing my total to 36 for this tank.

The thread that I followed in building this light, the guy had 48 (upped to 60) over a 75g reef tank and has had amazing growth and color over the last 18 months. Most people have said he doesn't have enough LEDs to light that size tank. This is why I say we just don't know yet what they can do for our tanks. Time will tell.

 

[kdogg85]

Wow, that is some output then. My hesitation is that I don't know anything about them. The only thing I understand about lighting is wattage and par. What I was planning is the routine of high light coral at the top and low light at the bottom with some moderate light in between. If I could see one in action, that would help me out more than anything. And over a 1000 dollars is more than I could swing(the wife will say no). Does faster falloff mean that the light disipates faster than what mh would? I will call pac sun and get a parts list and try to talk one on one with someone. Cmor, thanks a bunch for the help, I just need to put all this together and get a good understanding of what to do.

 

[kdogg85]

I know you guys are against ebay, but would what this light claims do the job?

Aquarium Coral Reef Tank High Power LED Grow Light 120W - eBay (item 390258701131 end time Nov-06-10 22:44:15 PDT)