MH W/G light rules

[Aeon]

If 2-3W/G PL/FL rule does not apply to MH, what does??

[tawauboy]

[quote:218db292a4="Aeon"]If 2-3W/G PL/FL rule does not apply to MH, what does??[/quote:218db292a4]

that is not a rule, just a guide.
think for mh, aquarist go with 1mh lamp for every 2'.

[lvanilla]

Is 2X70W sufficient for 5 footerX2X2? Is there any special MH bulb where it itself got uv filter or block?

[vinz]

I'm not sure how deep 70W MH will cut, but the typical 2ft height tank uses 150W MH.

[lvanilla]

Hi Vinc, I was told Mr Gan uses 2x70W for his big tank also. But he is growing plants like moses and other little light requirement plants. BTW his tank is slightly higer than 2 ft.Frm his tank, is the the intensity of light, izzit bight enu at the bottom?

I was also told by people 150W promote algae prolem too, any comments?

Thanks.

[BFG]

If you use a 2ft tank with a 150w mh, can confirm you would get algae problem. You need to take into account your tank size to the mh that you gonna use.

[lvanilla]

u meant can or cannot?

[BFG]

I think 2x70w for a 5x2x2 may not be enough. Try looking for Kingpin thread. He has the same tank as yours and has multiple mh lighting( around 4 pc).

[vinz]

For a 2'x2'x2' tank, you can use 1x150W MH.

For a typical 2' tank... 150W MH is too much.

[lvanilla]

Thanks. I had bought the light liao......70WX2.

[ahmiao]

[quote:15b12b54="lvanilla"]Thanks. I had bought the light liao......70WX2. [/quote:15b12b54]
can u pm me on where you bought and for how much?Thanks alot!

[patrickttg]

Hi ppl,

Just to join in the fun too on MH light, I got a 2'X2'X2' Tank with a pendant 70W MH and did some read up too ......No one seem to be able to agreed on the correct amount of wattage to go. BTW, I just had it for about 2 weeks, still experimenting leh

My thinking is that it depends on the temperature and the duration you had it on. I notice my tank temp. went about 1.5 to 2 degree when the light is on for a while hence higher wattage should drive the temp up further = to algae problem. Currently my light timing is the minium 8 hrs so I got 2 hours to play with the photosyn. timing. I had removed the frosted glass and on the way to replaced it with a clear glass...safety reason. My plant is a wild and crazy mixture of fast growing plant at the moment...switching to more moss spieces soon.

Cheers

[blur one]

I too had questions when I was researching for MH lights...in the end I went for 3 times 150W with 6700K (around there) for my 6 by 2.5 by 2.5.... The height of tank is high but after taking into consideration fertbase, gravel, gap on the top...I think should be enough. My lights are fitted into the false ceiling and they are 2 ft from the surface...some people say ok...some say too far.... but me experimenting also at the moment..... Plants are growing but the rotala is not red...but I suspect its the nutrients as I am not dosing heavily as Its a new tank. The bottom leaves are red but the upper leaves are greenish and light pink....I say its the nutrients because the upper leaves are nearer the light source so they should be getting enough light compared to the bottom leaves.... any comments ??

[Slan]

Hey everyone.

I´ve got a 125*125*65 tank- cm that is.

i´ve got 2*250w mh and
1*150w mh

Is this sufficient ? or maybe too much, i´ve got algea on the bottom already, not many plants they´re comin next week.. what do you recommend?

Greetings Simon

[BFG]

Hello Simon.

I guess your light is too much in my opinion. Your tank may need 2x150w the most! 2x250w is too much plus another 1x150w is already an overkill. 250w mh bulb are mainly used in a marine tank setup.

Maybe you could use 1x250w mh for your tank and raise it till it could illuminate nearly most of the tank interior. As a rough guide, start using the light for 6hr per day for the 1st 2 weeks. Subsequently add 2hr more every 2 weeks. Maximun is 12hr per day of lighting. 10hr is also good.

Or you could use 2x150w light. Change the ballast from 1 of your 1x250w mh light to a 150w ballast. With this combo, all your tank area will be illuminated.

Or if you do not want to buy or change your existing mh, you could still use the 2x250w. Maybe with this intensity, you could grow carpet plants like glosso. All of the tank area will be illuminated as well. The area surrounding the tank would be illuminated by this light too.

May I ask if you are going to use a chiller to cool the tank as the mh will definitely heat up the water. Or your local temperature is quite cool to offset the heat produced by the mh light?

[Slan]

Hey there.

Bfg,

i´m planning to cover the entire bottom with HC, and vesculiara on the stones.
2*250 would be ideal for this ?
i´m going to use co2 , tmg and some pmdd.

Maybe i should empty the tank now, and wait til I plant all of the plants so the algeae dowsent take over from the beginning..
Will the algea survive if i empty the tank, but doesent clean the gravel ?

Have a good one.
Simon

[Slan]

Forgot to say that the temperature is good here, around 23 outside now, and the summer i still to come the temperature in the tank now is 25c.

[BFG]

Simon, what's the water temperature if you use 2x250w mh. As for your algae problem, why not remove all the algae and do a water change. Vacuum or remove the gravel where there are algae present. You do have base fert under those gravel right? Don't vacuum or remove too much gravel or the base fert might seeps into the water column. Leave the water level till it cover all the gravel surface. There's no need to leave the tank full of water. Switch off the lights so that the algae doesn't grow.

When does your plants arrive? HC is a notoriously slow grower. I'm trying some too but my shrimps keep tugging it out often and I have to replant it again. Got a pics of that tank of yours?

[Slan]

Hi.

BFG, the water temperature is steady at 26 degrees, live in a cold country called sweden ;P
The algae problem was solved by getting some botia´s and some SAE.

http://www.zoonen.com/res/user/88526...65_orig_SE.jpg

heres the tank =) just filled up when i took this picture.

125*125*65cm 1015 Litres.

[BFG]

Wow Simon, finally got to see the tank. I see you are using eurobracing for the tank. Yeah, I know you live in Sweden. You could switch off 1 of the mh light until you have added more plants. 26 degrees is nice. In my country, you need a chiller to get that temperature. I have 1 tank that is currently using 1 with 26 degree just for keeping shrimps. Can't wait to see the end result. Thanks for posting the pics Simon.