my local shop has a surplus of 400's and is selling them cheaper than the 250's. my question is on a 120 (4x2x2) is it necessary to make the jump, and the reason i ask is because i am worried about the electric bill jumping up way more. will it? ive been told that my sps will thrive under 250's but will they do significantly better under the 400's? Also where have you guys found the cheapest prices on the retrofit metal halide kits?
250's or 400's
- Thread starter crb10
- Start date
prop-frags
SPS Slave
The amount of electricity pulled by a 400w bulb is a lot!
3.33 amps in the U.S. Contrast to a 250w bulb which pulls about 2.1 amps. A pretty good rule that I've read is if you have a tank depth of 24" or less, 250w will suit fine (especially if DE bulbs are used). IME, my clams are doing just fine on the bottom of my 180g which is 24" and I'm using DE 250w bulbs.
I'll go out on a limb here too - I think that using 400w bulbs in a tank 24" deep or less creates additional risk of things going wrong. Just as with running with an alk 11 dKH or higher, or at a temp of 82f or higher. It can be done, and people have done it with great results, but it creates faster metabolisms, and with that comes the risk of things going bad faster. You have to be on your toes and keep up the husbandry really well.
3.33 amps in the U.S. Contrast to a 250w bulb which pulls about 2.1 amps. A pretty good rule that I've read is if you have a tank depth of 24" or less, 250w will suit fine (especially if DE bulbs are used). IME, my clams are doing just fine on the bottom of my 180g which is 24" and I'm using DE 250w bulbs.
I'll go out on a limb here too - I think that using 400w bulbs in a tank 24" deep or less creates additional risk of things going wrong. Just as with running with an alk 11 dKH or higher, or at a temp of 82f or higher. It can be done, and people have done it with great results, but it creates faster metabolisms, and with that comes the risk of things going bad faster. You have to be on your toes and keep up the husbandry really well.
zapata41
In Memoriam
i had 250w on my 180, 24" tall. the growth and punch was fine but here is the kicker and this is what help me decide to switch to the 400w that i run now. with the 2 x 250w setup i am running 500w on the mh, add another 280 for the 2 x 140 vho, now i am just shy of 800w, all this to get a par of 115. so my vho ballast croaked and i decided to run 2 400w 20k bulbs, gives me a par of 127, and only runs at less than 850w. so to me it was simple. to others it may not be. also i was running the vho before and after the halides, now i just run the halides for 6hrs a day, natural sunlight helps in the late am hours.
Tim
Tim
zapata41
In Memoriam
i run the same number of fans from my 250w setup as with my 400w setup. just two 4" icecap fans. i think a common thing that ppl do i go get the 250w setup since it draws less watts, then go out and get a 10k bulb for the par, then go out and add 4 vhos to get good color back, then they are drawing more watts than a 400w setup
Tim
Tim
zapata41
In Memoriam
i just did the elec calc and my old setup actually costs more to run by 3$ a month than my 400w setup
funny. and my heater run less now. before i had to run the heater in the day time, hopefulyl now it wont come on at all in the day time, that will save me 600w just by keeping it off
Tim
funny. and my heater run less now. before i had to run the heater in the day time, hopefulyl now it wont come on at all in the day time, that will save me 600w just by keeping it off
Tim
REEF-DADDY
New member
I had to to do it over again, I would run 400's with a "blue" bulb and no supps. You can get par and color with the 400's.
Travis
10 and over club
3 x 250w is more than enough for sps anywhere in my 30" tall 280 gallon tank.
<img src=http://notlehs.com/travis/3-12-06%20full%20tank%20pics/141_4137.JPG>
I couldn't afford the electric bill in the summer when running 3 x 400 watts. Not really because of the added electrical consumption of the ballasts, but mostly because it required my chiller to run almost constantly and that sucker takes up 13 amps.
So dropping down to 250w was a no brainer for me. My chiller hasn't even kicked on since last August and it used to kick on several times a day in the winter with 400 watters.
The best part is growth actually increased when I swithed from 400w 20k's to 250w 10ks with actinic VHO.
<img src=http://notlehs.com/travis/3-12-06%20full%20tank%20pics/141_4137.JPG>
I couldn't afford the electric bill in the summer when running 3 x 400 watts. Not really because of the added electrical consumption of the ballasts, but mostly because it required my chiller to run almost constantly and that sucker takes up 13 amps.
So dropping down to 250w was a no brainer for me. My chiller hasn't even kicked on since last August and it used to kick on several times a day in the winter with 400 watters. The best part is growth actually increased when I swithed from 400w 20k's to 250w 10ks with actinic VHO.
prop-frags
SPS Slave
Ahhh the voice of experience...heed it well!
RichConley
New member
Most of the 250 10K are running much higher than the 400w 20ks, unless you're running 400w HQI, but then you're looking at 450+, and new bulbs every 3 months to keep that par.
250s is how I would go, but honestly, if you keep your water clean, 175s would probably work.
Horace
New member
All I know is the best tank I have ever seen, and likely will ever see in my life (as far as growth and colors go), uses 400w XM 20k, or other bulbs of similar color (not necessarly temp indicated by the manf). I am STRONGLY considering running the 400w XM 20k or similar on my 75g, just so I can have high par, with a 20k bulb. It is my opinion that 20k simply produces the best colors. unfortunately to get good growth you need more PAR...thus the 400w...
