Lower Light Levels - 100 days later

[Gerryd]

Hi all,

As you may know I swapped my 3x150w 6500k metal halide fixture for 2 T8 fixtures each with 4x30w bulbs.

The MH provided 50-60 micromoles at the substrate and over 100 at the water surface suspended 39" above the water surface of a 24" deep tank.

The T8 fixtures provide about 30 micromoles at the substrate and over 55-60 at the water surface suspended 6" above the water surface of the same 24" deep tank.

Some observations:

1). Growth is much slower.
2). Growth for some species is smaller but time will tell. The scape and plantings are still relatively immature.
3). There is literally NO algae anywhere of any type. Some GDA on the front glass and some brown diatoms from direct sunlight on one end pane. Previously I struggled with bouts of BBA and types of cladorpha covering the wood...
4). New growth is constant and consistently good. Leaf formation is good. No deformities in shape or color.
5). Trimming duties have almost disappeared
6). I do miss the MH shimmer and I am not sure I like the yellowish cast of these bulbs. Will be looking to replace with something better perhaps...
7). I spend LESS time playing with c02 and balancing it with the fish. It is pretty much set and forget. Just ensure the tank doesn't run out or the needle wheel tubing fall off...
8). Fish seem happier in the lower light, but I think I may be projecting
9). Growth is also thick. Perhaps not as lush as it might be for the same age as under the MH, but I am happy with it so far.

So, overall while I have lost some of the pleasure derived from larger and faster growth, remember my Blyxa?, I spend a LOT less time asking folks to take cuttings as well...

There are some plants I am sure that will not do well for me but for the most part I am using lots of java and anubias varieties along with some bolbitus and stauro....

No problems with growth so far..

I really recommend to folks to think about reducing their light levels if their goal is less trimming and maintenance. I don't stress anymore trying to ensure adequate c02 for aromatica stems that grow 1-2" daily

Thanks for listening.

 

[SuperColey1]

Low light is awesome. Coupled with no CO2 the only plant I have to thin out is the needle ferns

Glad you like it and it is working.

AC

 

[barbarossa4122]

Thanks for the tank update Gerry. I am waiting for the par meter to arrive in the next 2-3 weeks and then I'll know for sure how to deal with my lights. But, I think they will have to be raised another 4" to 16" above tank, 32" from substrate. I agree again............too much light is causing needless problems.

 

[fjf888]

2). Growth for some species is smaller but time will tell. The scape and plantings are still relatively immature.
\.

That's great, the above point is what I will be curious about as your scape matures. Are there some plants that will be dwarfs due to low light, even with adequate CO2. This could be manipulated to ones advantage perhaps in a smaller tank, could be problem in a larger tank.

Certainly your scape is a compelling argument for lower light. Also its a great reason to get a PAR meter to actually measure the light. The cost of the meter is much less than paying a whole bunch of money for light fixtures that are unnecessary.

 

[Tom Barr]

A good trade off, but color is still lacking I think to some degree vs Tri phosphors are LED's.

You still get the shimmer, but with about 1/2 the wattage of T5's roughly.
Or about .7-.9w/gal.

Also, folks complain about having to trim, this is a good argument for less light.

 

[Tom Barr]

FYI, I have both PC and MH lighting and it took me a long tiem to get off the MH's, I reduced their time from 4-6 hours, down to 1-2 and then off finally.

If you have nuke powered light, it is very tough not to bother using it.
I have electric cost to deal with and also heat and evaporation which leads to mold in the winter months, so less light is more pragmatic and practical on a few different levels.

LED's would cost a lot more, but I might end up going that way for the 180 Gallon I have.

Two banks of 30 three watt Cree 6500K with a mix of red and blue here and there inside the fixture I have would fit nicely. A retrofit job basically and add a dimmable transformer.

Be about the same lighting I now have.
A tad higher even.

 

[adechazal]

Ditto what you guys are finding. I have a 180g 60"widex24"x29"tall over which hang 4x80w 60" long T5HOs about 6" from the water. In a 10 hour lighting period all four bulbs are only on for 2 hours, the rest of the time only two are on. When I drop this down to 10 hours with only 2 bulbs on at any time the algae goes to nothing. I just miss the red plants as they seem to all go green without the burst of bright light.