T5's to MH

kau_cinta_ku

New member
I have been running an icecap 4-54watt T5HO retro over my 75 gal. for about 8 monthes now. but yesterday switched to 2 - 400watt 20k XM MH. i was wondering what would be a good way to acculimate my corals to this new light. i am gonna do the start of running the bulbs at a certain number of hours a day then increase it after a wile till i get to my regular lighting schedual. but what would be a good start? 2 hours a day and increase the lighting 1 hour every 3 days? or start off more than 2 hours?

BTW the MH are 9" above the water and the T5's were 3" off the water.

TIA
 

Percula9

New member
I would run just one light to see how they react for a week. Once you turn on the other light keep corals at the bottom and slowly move them up if needed. Can you run the lights separately or is it one fixture one switch.
 

kau_cinta_ku

New member
i can run them seperatly but I can't move the corrals without breaking them off and re attaching them which I am not about to do. lol and i don't want to run seperatly due to I have corals all over the tank and diff. kinds so even if i did run only one side where all the SPS are then i still won't know how well the leathers and LPS on the otherside will react later on. i hope you understand and thanks for the help so far.
 

mile sq. reefer

New member
Why would you run 400w bulbs on a tank that is less than or about 24" deep. Two 250's would have done the job easily. 400w bulbs are good for tanks 30" deep. Maybe you have a 30" deep 75, if not, overkill IMHO. Also you will be boiling the water if you dont have a chiller.
 

juniormc8704

New member
400w might be a little more than you want, but if youre an sps guy, than more the marrier. just go to Home Depot and get some plain old window screen. put about 10 layers over your tank, pull a piece away every few days. that should do it. just make sure you are NO closer than 12" from the surface of the tank.
 

DarG

New member
WOW ... Dual 400 watt MH's over a 20" deep tank.
I heard that Foster Grant is making mini sunglasses for fish. The Clown, Tang, Pygmy Angel and Damsel size models have been out fo a while. Sun Glasses for Wrasses, Gobys, Shrimp and Blennies should be out by August 1st. More models to follow as the summer wears on. :cool:
 

RichConley

New member
<a href=showthread.php?s=&postid=10424579#post10424579 target=_blank>Originally posted</a> by juniormc8704
400w might be a little more than you want, but if youre an sps guy, than more the marrier..

Completely untrue. SPS photosaturate pretty easily in clean water, and IMO, react more negatively to too much light than anything else.

You're going to constantly have bleaching issues unless you can keep a TON of nutrients in your water.
 

kau_cinta_ku

New member
<a href=showthread.php?s=&postid=10424608#post10424608 target=_blank>Originally posted</a> by DarG
WOW ... Dual 400 watt MH's over a 20" deep tank.
I heard that Foster Grant is making mini sunglasses for fish. The Clown, Tang, Pygmy Angel and Damsel size models have been out fo a while. Sun Glasses for Wrasses, Gobys, Shrimp and Blennies should be out by August 1st. More models to follow as the summer wears on. :cool:

that right there made my day. LMAO thanks i needed that.

also i don't see a prob. with it. ppl with 250 watt DE bulbs have the same amount of par as 400 watt SE from what i have read. also Lunchbucket has kept a 20 gal. tank with a 400 MH and corals were awesome. i can't say much about heat issues yet cause the lights are only on for 3.5 hours a day so far but even then the temp in my tank has stayed 79 degrees constantly but prob. due to the fans. and the bulbs are 14" off the water witch is higher than most that run MH.
 

aninjaatemyshoe

New member
Heat wouldn't really be an issue if your evaporation keeps up with it. I would worry about excess lighting. Someone saying they were successful in maintaning a tank with such and such Wattage halides is worthless information unless you know the following variables: how high did they keep the light from the tank? did they have a good amount of air circulation between the tank and lights? what bulbs/ballast did they use? what corals are we talking about? where were the corals placed? what lighting schedule? what reflector for the metal halide? To name the more important factors.

Sure you can keep corals under a 400W MH in a 20" or less high tank. Just raise the light (IMO 9" above your tank is too low for a 400W MH). The real question is why would you when you can get away with using almost half the electricity with a 250W setup?
 

kau_cinta_ku

New member
sorry i was wrong they are 13" off the water.

well the main reason is that i got a good deal on the setup and am planning on upgrading sometime next year and would be using 400 watters on the new tank anyway so it will save me from buying later.
 

The Grim Reefer

Ready for some NOBALL!!!
A 4 lamp Ice Cap T5 3" above the water to 400 watt 20K halides 13" above the water might not be the huge lighting increase everyone is assuming. What reflectors are you running with the halides?
 

ibmgeek

New member
Id imagine the icecaps were bright considering i have the old tek 4 54 t5 retro and i they bother my eyes when i look at them.
 

The Grim Reefer

Ready for some NOBALL!!!
The thing is even with a perfect Parabolic reflector on both (which doesn't exist) A lighting source 3" away from the water only needs 25% of the output as one 12" above to equal the output hitting the surface of the water. If the halides just have a flat reflector or a cheap curved one they may not produce a large increase. A 20K 400 watt Xm doesn't produce quite as much PAR as a XM 250 watt 10K HQI.
 

kau_cinta_ku

New member
the reflector is just the cheap spider reflector nothing fancy. so the way i am seeing it. for the cheap reflector and how high they are from the water I am not changeing my par as much?

which is fine with me cause i mainly did it for the shimmer lines but still wanted enough light with a 20K bulb and for when i upgrade
 

RichConley

New member
<a href=showthread.php?s=&postid=10427354#post10427354 target=_blank>Originally posted</a> by kau_cinta_ku

also i don't see a prob. with it. ppl with 250 watt DE bulbs have the same amount of par as 400 watt SE from what i have read. H.


100% NOT TRUE.

You'd be lucky if a 6500K 250DE has as much par as a 20K 400wSE. 250w DEs dont even have as much par as 250w SE.


Stop spreading misinformation.
 

The Grim Reefer

Ready for some NOBALL!!!
The Spyder reflectors aint bad. You got an increase but I think it's very managable. Someone already mentioned throwing a couple layers of window screen over the tank which probably wouldn't be a bad idea. Give it a week or 10 days and pull a layer and do the same thing again. Just make sure you get the fiberglass screen and not the cheap plastic crap..
 

DarG

New member
Rich, why is that misinformation. I was under the impression that 250 watt DE 10000K and 400 watt SE 20000K was, generally speaking, close in PAR. Just checking Sanjays site, there are many examples of this using his bulbs comparions, that seem to hold true. That's 250 watt 10000K DE to 400 watt 20000K SE, not even 6500K DE. Seems that there is a slight edge in par with the SE but in general it seems pretty close.

I dont think that kau_cinta_ku was intentionally spreading misinformation. Again, there are exceptions, but generally speaking, they dont seem all that far off.

For the 250 watt DE VS SE, I was surprised because I thought you were right that the SE was usually higher. But again, checking as many of the same manufacturers equivalent color temperature bulbs in both DE and SE versions that it was about even. Some manufaturers SE versions was higher than DE versions of the same K rated bulbs. But with other manufacturers, the DE versions of the same color temp. rated bulbs had higher par.
 
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