Lighting Requirement

[b_goh88]

I've one question on lighting which I don't quite understand. Appreciate some of you could help me on this.

Example:
If I've a 100G tank, and with the guideline of 2W per 1G. That means I need 200W lighting.

Is there any different if I use 100W lighting but turn "On" twice the amount of time?

[Shadow]

It doesn’t work that way. It is mater of whether the light able to reach the bottom of the tank with certain amount of intensity for foreground plant to grow.

That is why those watt per gallon thinggy does not worked with very large, very small and more than 2ft deep tank.

[torque6]

goh,

Lets try this approach. Let us know what tank size you intend to have or already have, and we will recommend the lights for you. Let us know the plants you have as well so we can cater specifically to your plant needs.

[b_goh88]

Currently mine is a 4 X 2 X 2 ft holding est. 100G. I use 4X 36W PL (144W) for the back part of my tank, and 2 X 28W T5 (56W) for the front part. Time On is 7.5hrs

Everything is ok, until I change out those lights after 1.5 years. The PL are ok, the T5 balasts died after changing new tubes, replacing the balast cost $40, I got the 2 new tubes for $30. I think it is more cost effective to buy a new set.

I'm just wondering, is it ok if I don't buy a new T5 set but use the PL with longer time, let say additional 4 hours.

I will be going to Sim Lim Tower to look for T5 balast (28W) this weekend. Any recommendation? Check the forum someone did mentioned 3rd or 4th floor a shop selling balasts and lighting.

By the way, is there any problem if I get a 54w balast and use a 28w tube? I'm thinking of changing to 54w T5 tube after maybe 1 year later.

[PROFILLET]

My experience shows that approx 250w to 300w would be ok for a 4ft .

[zenscape]

Why don't you change to a High Output T5 now? It will not be a problem to oversize your eballast. In fact some reported that it is good to do so.

What you are having now is sufficient for the tank of the size. But there are many factors to consider such as the type of plants you have in mind, and water parameter such as ferts, Co2, etc. Are you going for a high energy tank or low maintenance tank? A general guide is if every thing is on the high side (co2, fert, fast growing plants), a high light will be ideal to bring out the potential of the plants. For low maintenance tank with shady plants like ferns and moss, you can get away with low light with little of no fert or co2. It is all about balance.

[AquaObsession]

Electricity bills should be the same, if you have the same amount of watts right.

About temperature, a fan should do the job.

Check my thread (back breaking rescape) for more info. With MH lights, you will not have limitations on the plants you can put in your tank. 2 feet is quite deep.

[StanChung]

The answer is no, longer photoperiod does not compensate for lack of light.

You may get by with moss and shade plants on 144W in a 4x2x2 tank. IMO moss looks nicer with medium high light. You'll know what i mean when you grow some on branches near the light and those under the branch with indirect light.

My 5ft and 3ft tank are 440W and 216W respectively[both using MH and PL combos] and they can grow glosso and HG lawns.

As for your problem, it's for you to decide what's good for your pocket and looks nice.[equipment wise].

I suggest trawling in the reef forums for used MH luminaires. I got a nice Arcadia S3 for 200SGD. Change the bulbs to ADA white 8000K HQI bulbs and suitable pl's/fl's. The space created by hanging the lights is great for working on a tank.

Strictly my opinion and the ultimate to have are the Grand Solar 1's .

[jasonchua1982]

What are the implication of not enough lightings for a planted 4 ft tank?

I use to have 6 tubes of 36 PL lights but turn off 1 of the tube in front as i realise most of my plants are scaped nearer the back of my tank.

Will this lead to algae prob, I am having BBA in my tank, but seems to get better after i dose nitrogen fertiliser (test shows tat phosphate is much higher than nitrates previously)

[b_goh88]

Thanks for all the advise. I will try to change the ballast to a 54W type and will change the light next year since I just got those 28W and use only for less than 1 day.

I don't keep moss, most of my plants are java fern, tiger lily, some slow growing plant (can't recall the name) and "sun glass" ( in chinese, that what the LFS told me).

I'm using a auto ph meter to control the CO2, my KH at around 3 to 4dH (gives about ph of 7.2 to 7.6) CO2 auto cut-off at 6.7

MH (150W X 2) is one of the best lighting I've used, but has long changed to PL and T5. With the current electrical cost, I don't think I will change to MH again.

[b_goh88]

Why don't you change to a High Output T5 now? It will not be a problem to oversize your eballast. In fact some reported that it is good to do so.

What you are having now is sufficient for the tank of the size. But there are many factors to consider such as the type of plants you have in mind, and water parameter such as ferts, Co2, etc. Are you going for a high energy tank or low maintenance tank? A general guide is if every thing is on the high side (co2, fert, fast growing plants), a high light will be ideal to bring out the potential of the plants. For low maintenance tank with shady plants like ferns and moss, you can get away with low light with little of no fert or co2. It is all about balance.

Hi zenscape,

One more question that I hope you could help. Will there be a increase in electrical cost if I use a 54W ballast with 28W light compare with a 28W ballast with 28W light. Thanks.

[StanChung]

Yes, that's a given because you'll be overdriving the bulbs. [reducing it's lifespan as well]

[ct13]

Is the electrical bill higher using MH (2 x 150w) compare to T5 (4 x 80w)?

Seem like many complain MH consume more electric?

Regards,
Ct

[StanChung]

I think the math indicates the T5's would consume more.

However MH do need some PL's to fill out some the shadows caused by it's focussed light property.

[mordrake]

not necessary.
i was told by a reputable light importer that if the mh ballast capacitor is not efficient, it may use up more wattage than the bulb is rated for.

[Shadow]

That would be the ballast efficiency but it is apply to all, regardless MH, T5 or PL.

[mordrake]

not all ballasts comes with capacitors.
anyway, using cheap light sets with inefficient ballasts systems may not help you to save in the end.

abit technical but some info

http://en.wikipedia.org/wiki/Ballast_(electrical)

[Shadow]

not only capacitor, transformer also have its of efficiency factor. Regardless what type of ballast, there always enegy lost. The sad thing is this efficiency invormation never stated in ballasts (at least not at the ballasts that I curently have).

[StanChung]

not necessary.
i was told by a reputable light importer that if the mh ballast capacitor is not efficient, it may use up more wattage than the bulb is rated for.

That's if you're overdriving, underdriving your bulbs.