Lighting guidelines

[vic]

I was just reading a recomended lighting rule of thumb on an internet plant supply operation website. They are recomending 2.5 to 3 watts per gallon. For my 125g that would be 375 watts at the 3 watts per gallon rule. I should think I would have to get the poor blighters that are living in the tank sun glasses and replace the slime coat with about a 40 sun block! I also am not sure how I could get the fixtures to fit the top of the tank.

I would appreciate some rules of thumb for a planted tank relative to light requirements.

Thanks.

Edited February 10, 2006 by vic

[Dave]

Interesting, I just posted a similar question in the general section as far as getting more light into a smaller space. I find that the fish who will shy away from the bright light will use the plants as shade. The watts per gallon rule is dependant on what kind of plants you want to grow. Some low light plants will do just fine with 1wpg, such as java moss, java fern, anubias, etc.

I am going to do a quick search on the net and edit this post if I can find it. There is a chart of Takashi Amano's light requirements per gallon. I found it to be very interesting, as it seems that there is no set rule. It is more intuition and experience than anything.

edit: Here it is: http://www.fitchfamily.com/lighting.html

here is some info on some common plants and their light requirements: http://www.dwarfpuffers.com/plants.htm

More good info here: http://www.azgardens.com/newaquar2.php

Edited February 10, 2006 by Dave

[Milan]

Vic,

WPG rule of thumb is not linear with tank volume. For smaller tanks WPG is higher, more toward higher value, and vise versa. That's why it's given as a range. I have not yet come across any study explaining the exact correlation, but hey ... it's a rule of thumb. However, the range I know of is 2-4 wpg.

Also, THIS IS NOT A LIGHT REQUIREMENT, but a guideline as to when the CO2 enrichment becomes mandatory, and such tanks considered to be "high light" tanks. You can still grow plants without it.

You should not be concerned about how fish would adopt to higher light intensity. In the nature, the sun light is way more intense than anything you can put above your tank. And yep, ... lights are not cheap. If you decide to go with higher lights, you can kiss your stock fixture good buy and prepare for a bite on your budget ...

[Golfnut]

Yeah the 2-4 wpg is just a rule-of-thumb.

I've got an 80 gallon 24" tall that I have 4x32T8 = 128 / 80 = 1.6 wpg.

I'll let every one know if it works for my plants which are mostly low light ones...

-vals

-crypts

-java fern

- 2 swords (don't know the type, these will probably need more light).

Regards,

Andrew

[jvision]

Andrew, you'll be fine with what you have. Swords aren't really high-light plants - but they'll eat it up if they have CO2 and ferts!

You've got mainly root-feeders (except Java Fern), so stick in some slow-release fert-spikes or clay balls under the plants, and they'll be mucho happy! Then just leave 'em be. At about the 6-8 month mark you'll look in your tank and marvel at how much they're all taking off!

Edited February 15, 2006 by jvision

[grumpy]

Jason, what are the clay balls you mentioned?

I'm very new to live plants and not having much luck. I've got a similar low light situation, and also course gravel substrate. I have some small clay pots that I want to use to put my plants in, and I'm wondering what to use as a potting substrate. Never thought of clay. Can you elaborate?

Thanks,

Jim.

[jvision]

I've never made them myself, but have used them with root-feeders, such as Crypts. From what I recall, they are made from redart clay and fertilizer - I think it was just regular grained fert, but I'd probably use something like Jobe's Plant Spikes.

The articles I've read just say roll balls of clay w. ferts in the middle, bake 'em for a bit. When they're cool stick 'em as deep as you can in the substrate and don't mess w. them. They'll make a bit of a mess if they're pulled up.

If you're using clay pots, this would be a great way to go. Some people even put potting soil in the next-to-bottom layer, between layers of aquarium gravel or sand. If you're growing your plants in pots, you can fertilize them a little heavier b/c you don't have to worry about getting the ferts into the water column when the plant is moved.

HTH

[grumpy]

Jason,

Thanks very much for all the advice on both this and the 'planting in pots' threads. I tried a couple tonight. Put some potting soil in the bottom about 2/3 of the pot, got the roots well into the soil, and covered the top 1/3 with gravel. I found pots at Home Depot that are about 3" or so high and about 2 1/2" across. Which means I can set them on the bottom and with 3" of gravel you can't see the pot. I'll now look for more plants and try a few more the same way. I'll post in a couple of weeks on any progress I make.

Thanks,

Jim.