experiences w/de + se

[shawns]

im currently running 2 175w se mh over my 90g tank. im considering changing to 250w de mh and i have a few questions/concerns b4 i SERIOUSLY make a switch. i would also have t5/vho act supplement.

1. since the price of the de bulb is almost twice that of a se, what is the life expectancy of the de bulb?(i doubt it's double?!?!?)

2. will a 10k xm se bulb appear the same as a 10k xm de bulb??(sub. any manufacturer and kelvin)

3. are there any preferences/experiences that any1 has had that may sway my decision to either stay w/ what i have or make the switch.

 

you guys are awesome!!

[gastone]

Shawn,

 

I've found the price difference between DE and SE to be nominal. It's been a few years since I've used DE, but I can't imagine that there is that much difference. Lifespan shouldn't be any different/

 

 

IMO, DE are better served in a hood, as accounting for the UV shields in a canopy is a PITA (though they do make reflectors that incorporate them for your DIY ventures).

 

I like the versatility of SE. Lotsa bulbs.

 

Go here and you can check your own spectral plots for XM (and many other bulbs).

 

My recommendation would be to pick a lamp you like and work from there. Then you can chose which ballast to use with it, which reflector (or hood) to house it in.

 

If you have 175 electronic ballasts you may want to take a look at the Iwasaki 14k. Nice looking, very white lamp with par better than/as good as many 250w lamps.

 

Garrett.

Edited April 10, 2008 by gastone

[ErikS]

Do they last longer? Yes, but not enough to be worth making a decision based on - the return on investment would be a LONG time (maybe 14mos for DE compared to 12mos for SE).

 

Bulb cost is about the same, all depends on the quality.

 

At one point in time, when they first came on the market DE bulbs put out far more par for a given wattage. IMHO this was due mainly to reflectors - it's far easier to make a small reflector that performs well. At this point in time the primary reflector for SE's was the relatively poor performing "bat wing". Now? With reflectors like luminarc & others on the market the gap between DE & SE has closed considerably = I wouldn't make a decision based on that alone.

 

The only thing posted above I might disagree with is the choice of bulbs - yes, there might be more in number for SE...........but all things considered it's about even. You can find a bulb in either format that performs the same & provides the same color.............................EXCEPT Radiums - you can get close with some 20K DEs but as yet nobody has produced a DE bulb with the same color & PAR.

 

As mentioned, it all depends on what you want to do - what are you after?

[shawns]

im pretty sure ppfd is par?

 

i can tell you what i have...i have 2 14k hamiltons, 1 ge 6.5k t5 and a pure act t5. i think that i have a lot of lights voids and i thought i could kick it up a notch w/ more wattage.

 

what am i after? well, i thought originally of going w/ 4 t5s w/ 175 mh in my hood. the only way that would fit would be to do a flat reflector and 2 slr's. (2 t5's and 2 mh in the flat reflector.) with the understanding that the flat reflectors are inferior to those that rap around the bulb, i would rather not use a "sheet". on the other hand, i didnt want to use the bat wing either. if i used a flat reflector, would i make up for its ineffectiveness w/ the addition of 2 t5's? i dunno.

 

what would i gain by using de 250w mh if i use the mandatory glass shield? like g-dawg already said, i could just go w/ iswaki 15k's and add my t5's. i dont want to add to my light bill just for the sake of having bigger lights. i do have a shorty, so size really doesnt matter.

 

according to the thread that g-dawg refferd me to, 175w iswaki's have 86ppfd. after that, no one even comes close. on the other hand, again shielded, the evc 10ks put out the most at 154 ppfd. what do those look like???? xm's have 136 and i have seen xm se 10ks before and i will need vho super act to make those look good. i guess to answer my own question, i would gain about 50 ppfd. is that worth the cost of running additional wattage? i'm considering effeciency w/ my change of lighting. it may help w/ the WAF!

 

i do have an understanding that too much light is bad. where do i draw the line? maybe thats a new thread? maybe my aforementioned "voids" are a figment of my imagination? i do like the look of radiums, but lets say for the sake of this discussion we say that i get 70ppfd from those. again, is it worth it?? maybe i could get close by using de and actincs?

 

ill stop the rant and let some1 else chime in. it seems like i may have some inner conflicts/constraints....thanks sanjay!

[ErikS]

ill stop the rant and let some1 else chime in. it seems like i may have some inner conflicts/constraints....thanks sanjay!

Yes, ppfd = par. Really that's the joy of this hobby - there are no right answers..........and lighting can give one quite the headache.

 

I prefer the spectral plots by Sanjay - shows where the bulb is putting out the light. The PAR stuff? Not so much, IIRC it's not done in real world testing (open air). There are some threads on RC (if I could find it) showing PAR in tank. You'll find some MH put 700 or more at the surface, quite less deeper (naturally).

 

Check my thread in the member section - see comments about Radiums, given the PAR rating one would think they wouldn't be so hot..............but in real world use they provide plenty.

 

Note: I don't use Radiums.

 

Crucial question - how's your livestock doing? Anything you want to keep that you can't? (been unsuccessful with)

 

If the answers are "fine/good" and "no" then why change?

 

We can analyze the bejeezus out of everything in this hobby but it boils down to "how's the livestock doing"

[shawns]

you're right. if i dont have a problem, then why change? i imagine that we all get sucked into doing something, "better" just because we think that it will make it such.

 

have i had any problems? not since i up sized to the 90g. that was only about 2mnths ago. give me a chance. im sure I'LL have a horror sorry b4 too long.

 

what i think i might do is just wait a couple of months and get the iswaki 15k's. i think that i'll change 1 of the t5's to a super act vho. every1 suggests that they look different then both the pc and t5 act. maybe the other i'll make an AB+.

 

thanks again

[ErikS]

you're right. if i dont have a problem, then why change? i imagine that we all get sucked into doing something, "better" just because we think that it will make it such.

I don't know about "sucked in" to an extent we do it because it's our hobby...................of course there the other side - the philosophy my wife says I live by:

 

if it ain't broke, tweak it until it is