How much lighting?

[wazza]

How much lighting is neccessary per gallon/litre for a planted tank? Also do the 'Plant tubes' actually make a difference?

Thanks in advance

wazza

[PHL]

Depends on what plants, how deep your tank is, whether you are using CO2 and fertiliser. I have low light tanks as well as a higher light tanks. Unless you balance the light, CO2 and fertilisers, more light will just grow algae.

[grungefreek]

Hey,

The general rule i think is 2 wpg for low light plants, and about 4 wpg or a bit more for higher light plants like glosso. Yeah but as said before it has to be balanced between ferts and Co2, other wise algae.

As for plant bulbs, well if you look at the side of the pack they may have a spectrum shown, generally these will have large spkes in blue and red regions of the spectrum, this is what plants need to grow. Generally other bulbs dont have as big a spike in these regions and more in other regions, this is so the light appears bright to our eyes. So yes plant bulb should make a difference. I think generally the rule is a bulb 6500K or higher should be ok for plants. Atm im trying 5000K CF's and ill report how these go

[PHL]

As for plant bulbs, well if you look at the side of the pack they may have a spectrum shown, generally these will have large spkes in blue and red regions of the spectrum, this is what plants need to grow. Generally other bulbs dont have as big a spike in these regions and more in other regions, this is so the light appears bright to our eyes. So yes plant bulb should make a difference. I think generally the rule is a bulb 6500K or higher should be ok for plants. Atm im trying 5000K CF's and ill report how these go

I think now the thought is more the number of watts, especially when you are at 4W/gallon (BTW, US Gallon is 3.8L), because they will all have some useful spectrum, and plant tubes tend to not looks as bright, or as good for some fishes. Also for larger tanks, the rule breaks down somewhat, as you don't need as much W/gallon, but for deeper tanks you might need more.

FWIW, Amano uses about 1W/gallon...

[OziOscar]

Has anybody tried these?

http://www.nelt.co.jp/nhe_hp/brbr/brbr.htm

The specs read well, but if someone else has 'been there, done that' I would be interested to know the outcome both for livestock and for flora. Otherwise, it's pioneering time. :D

The spectral diagram for the 'BR' series looks pretty similar to that which I have seen on the box for the ones I have picked up at LFS and the like. The blue readings look a little low, so maybe it could be boosted with an actinic?

There is no mention of light colour temperature, just lumens ratings and spectral information.

Cheers - OziOscar.

[Brett4Perth]

Yeah, I have used the NEC triphosphor HG which has 5000K temperature.

Seems to do a good job, no complaints, but it is hard to compare as I have a couple of tubes and rarely use the same tubes in both.

Cheers

Brett

[OziOscar]

OK - 1 x positive, 0x negative... I'm a sucker for punishment. :D

I will install 2 x 3 ft tubes on my Mbuna tank and on a plants only tank (48") and report the results.

I will still add actinics to push the blue peak higher and create artifical dawn and dusk. Is there any reason that this could be considered bad?

Cheers - OziOscar.

[grungefreek]

I think now the thought is more the number of watts, especially when you are at 4W/gallon (BTW, US Gallon is 3.8L), because they will all have some useful spectrum, and plant tubes tend to not looks as bright, or as good for some fishes

If you use lots of watts from the wrong spectrum it results in algae. If you have 4wpg of 3000K it is general concensus that algae will grow more than the plants . Also these bulbs are yellow and dull and look crap .I think fish colour enhancing bulbs are about 5500K, so these would grow plants pretty well, and still appear bright. Yes most plant bulbs show that purple/pink colour, which some people dont like, but the plants like it . I think if you had ~5000K bulbs (minimum) with good amout of watts and CO2 and ferts, you will have a bright tank that grows nice plants. This is just my opinions, others will have other views.

[PHL]

I will still add actinics to push the blue peak higher and create artifical dawn and dusk. Is there any reason that this could be considered bad?

I don't think you need the actinic; just use more normal tubes. I know of some keen aquarist who uses a redder tube for dawn and dusk (from memory, it was a 5 tube setup, with the 2 red tubes coming on first and last, and the others coming on 1 hour after, and going off one hour before the redder tubes). I don't think there was any real advantage.

[PHL]

I think now the thought is more the number of watts, especially when you are at 4W/gallon (BTW, US Gallon is 3.8L), because they will all have some useful spectrum, and plant tubes tend to not looks as bright, or as good for some fishes

If you use lots of watts from the wrong spectrum it results in algae. If you have 4wpg of 3000K it is general concensus that algae will grow more than the plants . Also these bulbs are yellow and dull and look crap .I think fish colour enhancing bulbs are about 5500K, so these would grow plants pretty well, and still appear bright. Yes most plant bulbs show that purple/pink colour, which some people dont like, but the plants like it . I think if you had ~5000K bulbs (minimum) with good amout of watts and CO2 and ferts, you will have a bright tank that grows nice plants. This is just my opinions, others will have other views.

I think some of the guys on the AP mailing list have played around with a few different combinations, and found that as long as there are enough plants, and enough fertiliser for the plants to not check their growth (the Sears-Conlin paper gives some guidelines, but you will have to look at your own nutrient levels), and enough CO2, then there will be no algae.