[AUAV8R]

I have started a standard 75gal tank with two 48" t5ho lights set at 28 inches above the substrait, I reduced my photo period from 9 to 6 hours, and I am dosing metricide. I have a clay base with osmocote fert. (plan on using root tabs in a few months) with a layer of flourite above that, and capped with a mixture of gravel, flourite, and sand... am I setting myself up for failure?

 

[JasonG75]

Whats the wattage of each bulb (54w?) I think this is fine...and actually you could lower this quite a bit. I have my light maybe 5 in above the water line.


ON NM Above the Substate..

 

[mgumaer]

I've got a Tek Light 4 x 54w T5HO unit over a 75. I think the prevailing wisdom around here would be that this is too much light. In my case, it was until I started paying more attention to my CO2 set up. Without consistently injecting CO2, it was an algae farm. With consistent CO2, I have no algae issues. That having been said, I think my ferts and CO2 are still inadequate to maximize growth with that amount of light.

Matt

 

[Higher Thinking]

Typically with individual reflectors, two HO bulbs are perfect for an injected, fertilized tank on the top. I run 4 with a single reflector at about ten inches off the top. I have been playing around with it lately as I used to use just two of the bulbs with the fixture on the tank itself. Then I built a cheap suspension unit and started running them all.

 

[2in10]

Typically with individual reflectors, two HO bulbs are perfect for an injected, fertilized tank on the top. I run 4 with a single reflector at about ten inches off the top. I have been playing around with it lately as I used to use just two of the bulbs with the fixture on the tank itself. Then I built a cheap suspension unit and started running them all.

What made you decide to run all 4 bulbs? Was it the ability to mix bulb spectra?

 

[Higher Thinking]

What made you decide to run all 4 bulbs? Was it the ability to mix bulb spectra?

I like the idea of a suspension system as it makes the tank seem more inviting. That and the fact that when I only run two bulbs they are situated right alongside each other with only one reflector for the set of 4 so I didn't really feel I was getting a full spectrum of light across the tank front and back.

 

[MRoss]

too much light

I'm not sure that it is possible to have too much light. I say this because I have a 150 gallon planted tank that is exposed to direct sunlight (measured at 7000 foot-candles at noon) on this tank. As long as I maintain the CO2 and nutrients routinely, and have fast-growing plants, I do not have algae problems.

I have a large number of small fish in this tank that breed like flies (guppies, otos, and about 20 Pelvicachromis pulcher "Nigerian Green" of various sizes. The dominant pair (wild caught) is about to spawn again. Please forgive me for having so many P. pulcher in the tank...I had removed about 20 to take to my LFS, but missed the remaining specimens. Not sure how.

The CO2 system is an old MRK 2 calcium reactor that I converted to a CO2 reactor by replacing the calcium media with bio-balls. It is controlled with a Pinpoint pH controller.

FWIW,

Mike (this is my first post, so be kind

).

 

[Hoppy]

I'm not sure that it is possible to have too much light. I say this because I have a 150 gallon planted tank that is exposed to direct sunlight (measured at 7000 foot-candles at noon) on this tank. As long as I maintain the CO2 and nutrients routinely, and have fast-growing plants, I do not have algae problems.

I have a large number of small fish in this tank that breed like flies (guppies, otos, and about 20 Pelvicachromis pulcher "Nigerian Green" of various sizes. The dominant pair (wild caught) is about to spawn again. Please forgive me for having so many P. pulcher in the tank...I had removed about 20 to take to my LFS, but missed the remaining specimens. Not sure how.

The CO2 system is an old MRK 2 calcium reactor that I converted to a CO2 reactor by replacing the calcium media with bio-balls. It is controlled with a Pinpoint pH controller.

FWIW,

Mike (this is my first post, so be kind

).

Plants will grow with "too much light", no question. But, if the definition of "too much" light is light that is so bright that you have a constant struggle to maintain good CO2 in the water, the plants require twice a week pruning to avoid having far too much plant mass in the tank, and avoiding big algae attacks, especially BBA, requires constantly removing beginning bits of algae every day or so, and the tank has become a onerous chore instead of a pleasure, then you can definitely have too much light.

 

[MRoss]

Hoppy:

I very much see your point. In my case this tank started out as an experiment because I wanted a tank that didn't cost so much to run...electricity costs here are extortionate.

The CO2 is pretty much "set and forget" with the controller and the 20# tank lasts a number of months. When I trim the plants, the main thing I have to worry about is taking out too much at once, as that can cause an algae bloom (green water only), but that is resolved in a couple of weeks. Also, the water is very soft with about 3 dkh at the moment so I don't use as much CO2 as I used to. When I do trim, I have a LFS that accepts any plants I bring as his only other source is out of town.

My biggest issue over the past several years is how to deal with the tank when Winter arrives. The lower light levels and shorter duration of sunlight means I have to play with the nutrient additions mostly. When I can afford it I may look into LED lights for Winter.

Given your feedback, I think I may look into some sort of lattice cover for the tank to decrease the intensity, something I can remove in Winter for a more consistent light level.

I should also mention that this tank is in an atrium covered with glass that is treated so that little infrared wavelengths are admitted. I actually have to use heaters to keep the water warm enough (the tank is also right next to two evaporative coolers) even though its 99-100 degrees outside now.

I appreciate your insight!

Mike