Need to slow down plant growth...

[MythT]

I want to slow down the growth of the plants in my 55g. I'm getting tired of keeping up with the trimming.

I have 2 65 watt CF lamps(6,700k & 10,000k) sitting on 2 inch legs above my aquarium which is co2 injected.

I'm kind of stuck deciding between getting 2 new 55 watt CF lamps at a cost of about $50 plus shipping or just trying to raise the light fixture up.

Which option would be better?

If I raise the light fixture up higher, how high up should it go and how do I actually go about doing that? The fixture doesn't have any place for attaching chain or wire for suspension. Plus I'm not sure what to do with the power cord which plugs in beneath the aquarium? Just let it dangle from the fixture? I'm not really concerned about light spillage at this point.

What do you think?

 

[Gerryd]

Hi,

Part of your problem is the amount of light and the fact you are using c02.

You have a high amount of light for that size tank.

The new lights will only be several watts lower and will still cause higher growth rates.

IMO I would mount the lights so they can be raised/lowered as desired rather than replace the lights.

You can do this in several ways if you look around. Some options:

1. Use metal conduit and bend to an L shape. Mount these to the cabinet. Then hang/suspend the lights from the conduit 'arms'. The cable suspension hardware should allow you to raise/lower.

2. Suspend them from the ceiling.

3. You may have to modify your fixture to add mounting hardware or an eyehook or similar.

4. Use basic closet shelving and simply place the fixture across the arms just like a shelf. This is easy and cheap(I do this) but the arms do cut across the bulb so a small shadow may be generated. The hardware has multiple slots for the 'arms' to go. Easy to raise/lower.

Hope this helps.

 

[MythT]

That is one thing I was wondering about. Two 55 watt lamps only brings it down to 2 wpg from the current 2.36 wpg. Like you said, it may not be enough of a reduction to simplify things much. I don't mind weekly water changes but am growing tired of every 4 day trimmings. Where as with suspension I could play around with things maybe better to my liking.

All that being put aside, what would be a recommended wpg to aim for to slow things down and at what point would I need to consider doing away with the Co2 injection and going with excel instead? Or could I just reduce the bubble rate of the Co2 going into the tank?

 

[Gerryd]

Well, assuming you can raise the lights, I would start at 6" above the tank and go from there as this is 3X the current height. It may take several weeks to guage the effects good and bad.

If you eliminate the c02, you may want to investigate the non-c02 low light setup described in this forum. Sorry I don't have the link/thread handy....

Don't just lower the c02 by itself, do it in conjunction with the light changes. Less light=less c02/nute demand=lesser growth rates. You can also dose your ferts in accordance with c02 and light and lower the ferts and c02 as you raise the lights.

IMO you want to be between 1 and 1.5 wpg but that is just a guess as wpg is not very scientific or accurate as a measure of light intensity........

That is where the PAR meter is handy, you can measure at the same spots at different heights to really see the difference quickly.

Without one, you will have to guage plant growth, overall tank health, etc to see where you are at. A good investment..............

First get the lights mounted/suspended so you have a good deal of adjustment either way so you can experiment. I can raise mine way out of the way if I have to but still light what I am doing and can go from 4" to 28" above the surface. Just food for thought..........

You may want to go back to higher light/c02 in the future and this allows you to do so with the same fixture.

Hope this helps.

 

[Tom Barr]

A simple thing you can do is also place white filter material, plastic, glass etc, or scruff what is there if you want, to reduce the light in the hood's panel inside the glass protector etc, I think you should likely raise the light up instead and go about 8-10" up with electrical conduit style hanging hood, and use the Coralife suspension kits, drill a hole into the hood and attach the connectors. Then simply make a loop at the top and slide on the electrical conduit pipe to adjust.

You can also simply chose different plant species which are easier for you to care for, or trim by "topping" etc.

There's 3 different things.

Regards,
Tom Barr

 

[MythT]

I think a switch to some easier to manage plants is something I will likely be doing after completing some research on what would be better for my setup.

I'm beginning to really like the idea of suspending the light.

I will check into the Coralife suspension kit, but will likely just mount to the ceiling since I have plaster walls with lathe boards behind and white ceilings which are easy to repair if I move the aquarium elsewhere.

I was already looking at the Current Orbit/Sunpod hanging kit and considering drilling two correctly spaced holes in the plastic endcaps of my satellite fixture and attaching the mounting hardware with screws. Of course, I need to remove the endcaps first & look things over to see if this might be possible.

Does anybody have any experience with the Current hanging kit? I like the looks of it a little better (all silver colored) or would I be better off with the Coralife suspension kit for simplicity sake?

Thank you Gerryd & Tom for all of your suggestions thus far.

 

[ccLansman]

if the kit is too much $$ you can run the suspension yourself. Didn’t catch what you currently have for a fixture but i took apart my coralife 48" and reused all the parts except for the housing and mounted the lights inside a custom hood. Was able to raise them to "9 above the water, really helped the light spread and from observation has caused my glosso to grow out along the substrate instead of up. If you can do something similar you can drill a hole in the aluminum frame, mount two loops. Buy metal cable at home depot and mount it to two ceiling studs and then into the loops. The cable is cheap and can easily be adjusted for height.