How many wpg is recommended?

[fiftycal]

Long time no post.


I'm fed up of having all my nice plants dieing, and only crappy plants living, so I feel like buying some nice new metal halide lamps for my 6x2x2.

I currently have 4x 4foot T5 HO, which quite frankly suck, considering that my latest hobby is buying extremely high quality and high power torches. Its just not right that someone who carries around a portable sun does not give a stationary sun for his fish tank!

I was looking around online, and I found a unit that has 3x250w metal halides and 4x80w T5s. This gives a total of 1070 watts, which is almost 6 WPG. There is a similar unit with 3x 150w metal halides instead, with the same T5 bulbs, giving 770 watts for about 4.3 WPG.

I realise 6WPG would probably be better for my plants, but unfortunately for my plants, I have discus. Would 6, or even 4.3 WPG be too much for my discus?

I have CO2 injection and I fertilise, but right now it seems just to be fuelling the algae :P

[ILLUSN]

mate good to see you again, what are you trying to grow?

value for money I've been using a 4x96w CF unit on my 6x2x2 and to be honest with the co2 cranking I've turned off 2 bulbs.

you dont need heaps of light unless your going for a glosso/HC carpet. whats your substrate like?

[DiscusDave]

6WPG is huge, the more wattage you use the harder it is to get the perfect balance between lights, CO2 and nutrients. I wouldn't use more than 4wpg, ideally 3 - you probably want to increase you CO2 and make sure you're dosing potassium regularly.

[aquafrogstuff]

I have a 6x2x2 (approx 700L) running 3x150W MH with 4xT8 fluoros. I've found that adding CO2 allows me to reduce the lighting levels and durations.

Your biggest issue with 3x250 plus 4x80 is the electricity cost, depending on how you run them. Its over the top, even for a marine application.

I've based my tank on a rating I found in the next that states;

"2-3 WPG - Medium, most aquatic plants will grow fine"
"3+ WPG - High, almost any aquatic plant can be grown"

I've found that when my MH come on, which is only for four hours/day in te middle on the day, that the discus do tend to hide from the light. That's one of the reasons, apart from the electricity cotst, why I reduced their run time and left the fluoros on longer (9hrs/day). When the MH come on, they run with the fluoros, so I'm burning something like 550W for that 4hr period. It becomes expensive.

Hope that helps.

[fiftycal]

Cheers!

I plan to go with the 150watts and run the MHs for 4hrs a day, with the T5s for the rest of the day.

I like to go for overkill, but I guess overkill would result in a massive amount of algae.

Time to go buy more ferts...

[aquafrogstuff]

Yes, algae! One of the reasons I went with the reduced run time for the MH is the algae. If you go with 3x150W MH with some fluoros it will be slightly over the top (not as bad as the 3x250W) but at least you can throttle it back if you're having algae issues.

[aquafrogstuff]

Yes, algae! One of the reasons I went with the reduced run time for the MH is the algae. If you go with 3x150W MH with some fluoros it will be slightly over the top (not as bad as the 3x250W) but at least you can throttle it back if you're having algae issues.

[XPLOSV]

Give Barr report a read, I learnt many thing from this forum regarding planted tanks.

http://www.barrreport.com/barrreport.php

I agree with ILLUSN, you dont need MH to get good plan growth. 4 T5 54W is plenty for your tank.

I think it's best keep to Low light with CO2 planted tanks. This offer excellent growth rates with less work.

[AHC]

I run 3 x 150W MH on my 5.5x2.5x2 (780L) tank and have 1 - 2 on at a time. I have two on at a time for a period of 1.5 hours.

Basically ive timed the lighting to come on from one side of the tank and move over to the other with a slight overlap of 1.5 hrs in the middle of the tank. The total light period is 5 1/2 hours (which will probably increase once i finish planting more plants).

Doing this has been successful for me as i have had no algae, good plant growth as well as giving the look that the sun is moving across the sky - I kind of simulate tree branches breaking the suns direct light which is only the metal halide turned off. The darker areas in the tank give fish a break from light if they like. They seem to love it and spend more time swimming around knowing they have a safe darker haven if they need it.

Maybe try something similar?