# Low/Medium light recommendations for 75G



## Harry Muscle (Oct 17, 2007)

I'm looking for lighting recommendations for a 75G tank (48" by 18" by 21" deep). Based on my calculations it seems like a fixture with 2 T5NO bulbs with a very good reflector would suffice or possibly a single T5HO bulb fixture with a good reflector. Unfortunately both of these don't seem to exist. So I'm wondering what people would recommend for lighting this tank in order to achieve low to medium light (in order to avoid CO2 and minimize algae problems).

Thanks,
Harry


----------



## Aquaticz (May 22, 2009)

Just took this quick picture to show you what a Finnex ray and a Catalina one bulb t5ho looks like. btw today is the day I do WC and some glass cleaning

not sure why the pic is posting mutiple times.










Regards,
Aquaticz


----------



## Michael (Jul 20, 2010)

I feel your pain! No one seems to make a fixture for the middle zone between light intended only for fish viewing and high light. One possibility would be a 2 tube T5 HO fixture that will operate with only one tube installed. You will probably need to ask the manufacturer about this.

Another possibility is a 2 tube T5 HO with one good plant tube and one Coralife Colormax tube. Tests with a PAR meter show that Colormax tubes produce almost NO useful light for plants.


----------



## Aquaticz (May 22, 2009)

What you are looking for is made Custom by Catilina Lighting. I think it best to call the guy, he is very helpful and the price is right. Make sure you get the plastic that protects the bulb from splashing. I also suggest you measure the length, as i have 2 tanks that are supposed to be 48 inches but each is a little different and he charges nothing extra for this service


Regards,
Aquaticz


----------



## Black Hills Tj (Jul 19, 2013)

Michael said:


> I feel your pain! No one seems to make a fixture for the middle zone between light intended only for fish viewing and high light. One possibility would be a 2 tube T5 HO fixture that will operate with only one tube installed. You will probably need to ask the manufacturer about this.
> 
> Another possibility is a 2 tube T5 HO with one good plant tube and one Coralife Colormax tube. Tests with a PAR meter show that Colormax tubes produce almost NO useful light for plants.


I'd go with a 2 tube T5 HO fixture. This will give you the option to dive deeper into plants in the future, and in the meantime, you can run something like an Actinic in one socket that will give your fish good color without causing algal growth, while having a 6700k or 10000k in the other for your plants.


----------



## jeff5614 (Feb 15, 2006)

I have the light that I've linked below from Catalina. I did PAR measurements outside the tank when I first received it using Giesemann Midday bulbs that were around 6 months old. The fixture is setting on the tank's rim 18 inches above the substrate. At that height, PAR measured 42 with one light and with two bulbs it was pretty much double at 80. These were taken outside the tank using a DIY PAR meter that I put together using a lux meter from a thread on TPT by Hoppy.

I had an older Catalina fixture that this one replaced. The older fixture had PAR of around 30 for 1 bulb and mid 50's with two bulbs. I'm not sure if the difference was due to the reflectors on the old fixture getting some water stains, the newer fixture having wider reflectors with the bulbs spaced more widely or a combination of both. I attribute the difference, although I have no real evidence, to the wider reflectors.

For my fern based tank, one bulb is plenty.

http://www.catalinaaquarium.com/store/product_info.php?cPath=71_198_200&products_id=1842


----------



## Michael (Jul 20, 2010)

Jeff, that is a nice fixture!


----------



## jeff5614 (Feb 15, 2006)

Michael said:


> Jeff, that is a nice fixture!


I've been really happy with it. It did take me a bit to get used to the idea of just using one bulb instead of two as I did with the previous fixture. Jim at Catalina is a pretty nice guy. The older fixture I had mentioned using was a modification of the 2x54 fixture they were selling at the time. He put two switches and two cords on the fixture for me before they were offering a stock fixture with that configuration at no additional charge. Admittedly it's not a Tek or ATI but I think they're hard to beat for the price, especially with the customer service it comes with.


----------



## kendrid (May 17, 2010)

I have a Catalina 4xT5HO fixture with 4 switches. I usually just run it with two lights on. My tank is a 90g and I have a 30" fixture and it works fine. I put low light plants on the sides and the reflectors spread the light nicely all around the tank.


----------

