Need to slow down plant growth...

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.

 

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.

 

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.