Light Intensity, 70MH or 96wPC - Page 2

phenom5 · #26 10/28/2007, 05:09 PM

Quote:

once i went with metal halide, i will never go back to using PC's.

exactly.

nietzsche · #27 10/28/2007, 09:23 PM

get the metal halide! i had a 70w mh fixture over my 10 and everything thrived. for my biocube 14 i went with the 70w mh sunpod fixture. ill never go back to pc

phannay · #28 10/28/2007, 10:31 PM

would a 70w sunpod be enough for keeping clams in a 12g?

Bmgrocks · #29 10/28/2007, 11:32 PM

I would think so, the lighting in a MH penetrates much deeper than any pc light, if you are worried about light intensity, go with one of the less light intensive clams, like a dersa, and do supplemental feeding, which is usually required when the clam is under 2" anyways.

I Just ordered my AP 12 70HQI and it should be here within a week, from DFS, ready to see how it will turn out...

Unsure of what route to take, in my 10 it was bta anemone dominated, but a mixed reef, like my AP 24 allows a greater assortment of corals.

I'm planning on the same matinence schedual, weekly 20% waterchanges, the use of my AC 70 Modded Fuge, and will probably pick up dosing with the Kent Nano, 2 part supplement. (use in my 24 and love it.)

bboy aqua · #30 10/28/2007, 11:52 PM

Quote:

Originally posted by phannay
would a 70w sunpod be enough for keeping clams in a 12g?

i think it should be enough if u place the clam more in the upper section of your rockwork

i have a crocea in my 10g under the 70w sunpod fixture and i keep it near the top of my rockwork
so far its been doing fine and ive had it for about 4months

heres a pic of it

phannay · #31 10/28/2007, 11:56 PM

i like the look of clams in the sandbed though. the 150W should be perfect for that right?

bboy aqua · #32 10/29/2007, 12:57 AM

the 150w should be enough
but for croceas and maximas keep an eye on them and if they need to be moved up then do so

puckbs · #33 10/29/2007, 03:30 PM

just to reiterate.....

on a 20h,
i would be better off with a 70w mh than 96w pc or 96w t5?

Bmgrocks · #34 10/29/2007, 03:33 PM

I honestly think, if you are able to afford MH go for it, pref a 150w, I think that 70w over a 20gallon tank may be too little to notice any significant differences over ur 96w PC, Anyone else like to comment.

There is a used 150w Sunpod in the used equip forum..

kydsexy · #35 10/29/2007, 04:28 PM

ok so here's something i learned the other day. i went to my lfs and in his 33L with a 130W Power Compact I see a bunch of frogspawn. a few zoas, and of all things in the world a 2-inch clam! So I ask HOW? and he tells me that the sucess of clams depends on the amount of lumens reaching the depth to the water and not the wattage per gallon of water. So I think gonna put this to the test.

And on another note, before all rude or sarcastic comments come. I've worked with the store before and never realized that all of his small clams start out in this tank and are moved to higher lighting and larger tanks as the grow past 5 inches. He takes his fish very serious and just bought a 48" LED light for probably the most gorgeous tank I've ever seen! I'll post pics. The LFS is Aquarium Conservation in Cromwell, Ct. Stop in and chat with Jim sometime!

jeremyj0247 · #36 10/29/2007, 11:08 PM

what about the cost of running a MH. Is the difference in the electrical bill noticeable. I have heard MH's are a lot more expensive to run, but I am not sure I have never had one.

nauticac4 · #37 10/30/2007, 10:01 AM

I run 2 x 250 MH over my 120 and it adds about 35 bucks a month to the power bill.

Running a 70W or 150W would use 5-15 bucks of power a month depending on how many hours a day and what your utility company charges for power.

InsaneClownFish · #38 10/30/2007, 11:14 AM

I think if I remember correctly, when I did the 150w HQI on the electrical calculator, I came up with $3.47 per month running 6 hours per day. I was afraid of the cost too, until I did a little more research and used a few of the electrical calculators with rates for the Northeast(very high). I was comparing this to an LED system that cost $850. My beautiful HQI pendant cost $206.95. The LED system running at closer to 8-10 hours a day would cost $1.77 a month. So yes, it costs almost double...lol...but it's $1.70 difference.

kydsexy · #39 10/30/2007, 11:24 AM

i just noticed the par and lumens comparison on the other page and i was wondering if that person used the same type of light 6000K 10000k etc. will they be so drastically different?

puckbs · #40 10/30/2007, 11:25 AM

in all fairness to that though, how long do the led fixtures last vs how many times do you need to replace the hqi at what cost per bulb?? STILL really tough to justify almost 1k on a light for a 20g tank...lol

Bmgrocks · #41 10/31/2007, 11:10 AM

Im unsure of how long LED's last, but i kno it can be over a year and up, As far as when to replace an HQI, i would do so every 8 months or so...any input?

puckbs · #42 10/31/2007, 02:22 PM

i think i had read that the led's last upwards of 8 yrs.....and i'm sure someone will have info saying otherwise..

m2434 · #43 10/31/2007, 05:53 PM

The PAR values provided seem a bit extream. Unfortunately I can't find any great comparisons. The best I could find is this.
Although written with planted tanks in mind, does provide some very good info.

Bulb comparison

If anyone knows of a well controlled comparison I'd be intrested in seeing it.

Bmgrocks · #44 10/31/2007, 06:43 PM

This was taken from Aqua Botanic Lighing, the link you provided and i found it intresting

"The most efficient bulbs in the sample are the metal halides, the high pressure sodium, and the tri-phosphors ADV850, Dulux, Pentron HO, and Aquarelle, about 20-30% more efficient than the average fluorescent. Of note is the comparison of bulbs with same spectrum but different power. The PC6700 with 55 Watt power is significantly less efficient than the 96 Watt version. This trend should be true for other fluorescent types as well, and also for the MH types. Interesting enough, a generic, traditional metal halide does not perform so well when put side by side with more evolved types such as the dense-line emitter MHs (MHN, Iwasaki65 and Optimarc)."

a few terms
MHN-Phillips dense line emitter MH 4100k CRI 80
ADV180-Phillips advantage Flourscent

quite a read....Give it a look

puckbs · #45 10/31/2007, 06:56 PM

yeah, a WHOLE lot of words.....where were the pictures and diagrams???? lol

Bmgrocks · #46 10/31/2007, 07:04 PM

yeah i wish there were, none....but it was intresting, it seems like in the fw hobby they condone the use of metal halide, and really push Power Compact, mainly due to the color spectrums offered. Unsure of when this was written, and assuming that they didn't use Marine MH, i can understand why, they are using the 3500k and 65k color spectrums, the amount of heat generated is one thing, but the Gross amount of yellow that is used probly turned them off to MH, the PC's offer a much whiter spectrum, and the Blues are useless in freshwater Aquaria.

Sounds to me like we need a SW comparison... as helpful as FW was..

m2434 · #47 10/31/2007, 10:02 PM

A VERY brief summary of my interpretation of the article, is that PAR/watt is best with MH's (out of the types typically used in a reef tank). High output fluorescents are potentially more efficient under certain circumstances, such as if driven by over sized ballasts and compact fluorescents are less efficient, but not by as much as suggested elsewhere (It is a good read, so don't take my word for these statments).

Of course, I'm still not sure PAR is really the best measure for reef tanks, as the measure was developed with green plants in mind. And would still like to see a well documented experiment with corals.... or at least with a really good light meter....

sammy33 · #48 10/31/2007, 10:37 PM

Quote:

Originally posted by jman77
sammy33, is that the 14 bulb in the sunpod?

I used the Ushio 20K lamp in the PAR tests. The lamp (and ballast for that matter) was about a month old when I took the PAR readings. I also tested the current usa 14K 70w lamp that came with the sunpod fixture and the PAR was a bit lower only topping out at about 390PAR.

I never tested my 32w PC retrofit that I used on my mini bow 7. I should throw it back on there and see what the PAR is?

m2434 · #49 10/31/2007, 10:51 PM

Sammy33, your PAR values still seem way high, do you have more info on how your measuring...

Also, I found this thread, may be of intrest.

250MH PAR thread

sammy33 · #50 11/01/2007, 08:13 PM

Quote:

Originally posted by m2434
Sammy33, your PAR values still seem way high, do you have more info on how your measuring...

Also, I found this thread, may be of intrest.

250MH PAR thread

Yes I have noticed that too. But there is not many other published readings (like mine) to compare to.

I have looked at that thread you linked and joe's measurements many times. I have also studiedSanjay Joshi's work on his site. I also reviewed the data from the bulb comparison link earlier in this thread. It seems that all of these PAR readings were done using a lab style setup to isolate the bulb/ballast performance (no reflector). This is usually a black box style setup with the light sensor mounted some distance from the bulb.

All of my PAR readings were done in situ. I literally stick the sensor in the aquarium and record the reading at that point in the aquarium. I have a 24" length of pvc pipe marked every 6" to hold the probe. The bottom of the pipe has an elbow to hold the probe in the correct position facing up. I try to take the readings directly under the reflector or as close to the center as I can get with the probe.

These readings simply show the PAR in that particular tank with that particular light setup. I am not using any conversions or compensations but just recording what the quantum meter reads on the probe at a certain depth in the tank.