Lighting help please

[thegasman]

I would like to ask for some lighting reccomendations for my 20" cube tank that I plan to run as a high tech set up. Some of the options that I've come across are Current USA 18" double T5, used Current USA 150 watt HQI, and a 70 watt version of the same light. I currently have a single Marineland Aquatic Plant LED and have thought about adding a second one, but still don't know if that would be enough for the 20" cube tank. I've also thought about adding the 18" double T5 mentioned above to my current LED fixture. I would like to avoid hanging a light from the ceiling and would prefer some type of rim mount light or one that could be placed on my glass canopy. I would like to be able to grow a nice carpet of HC in this tank along with other TBD plants. Let me know if more details are needed.

Any reccomendations would be greatly appreciated.

Thanks!

 

[Gerryd]

Hi,

I would not advise any HQI for a 20" tank

The twin T5 is good but overkill IMO..If resting on the little legs will overwhelm you with light. You may need to use shade cloth and/or floating plants since you cannot/willnot mount the fixture.

I think a good twin T8 fixture would be fine for your plans....

 

[thegasman]

Thanks for the input Gerry and sweet 220 BTW. Yeah, I don't want to use the little legs on the T5 or hang a light since this tank is in my living room and I don't want to be blinded when I look at the tank. The tank is a 20" cube so obviously it's 20" deep. I just wanted to confirm that you saw this and if you still think that a twin T8 will penetrate enough to reach the substrate with enough light to grow HC. Someone that I trust and respect at a LFS reccomended a 6 bulb T5 which I thought was total overkill. What do you think about adding a second Marineland Aquatic Plant LED? They are pricey for what you get, but I like the sleek look. I appreciate the help as this is my first planted tank.

 

[dutchy]

I don't think a twin T8 fixture will give enough light to grow HC well. I also have a non CO2 tank with two T8's and reflectors and I can't get more than a PAR of 35 mmols at 20 inch. T5's with good daylight bulbs are much better, but still might not give you more than 50 to 60 mmols. Basically you'd need 3 T5's.

 

[thegasman]

Thanks dutchy. WOW that AGA entry in your signature is outstanding! I didn't mention it in my original post, but I do have pressurized co2 with a GLA in tank Atomic diffuser running at 3 bps and 35 psi. My tank looks like a glass of soda water which I don't care for, but my drop checker seems to be the correct color. Anyway, do you think that getting a twin T5 (very limited selection of 20watt T5 bulbs) plus my Marineland Aquatic Plant LED would work well? I like the shimmer effect of the LED. I wish there were some actual PAR readings around for my LED besides what the manufacturer has published. I'd like to be able to use two of these LED fixtures, but am concerned that they wouldn't be enough and the twin T5 is much less expensive. I've tried to find a PAR meter to rent in my area (Arizona), but haven't had any luck yet.

 

[dutchy]

I don't have experience with LED fixtures, so I really can't say. If you keep the LED fixture in the front where the HC is, it might be enough.

 

[thegasman]

I've been moving the LED to the back of the tank for half of the photo period and then to the front of the tank for the other half of the photo period for the last week. I added the HC to the tank last week and I have a little growth but not too much. I did get about an inch and a half of new growth in the last week with some Pogostemon Erectus that is in the back of the tank if that's any indication. My Echinodorus bleheri is also growing very well with lots of new growth. I think both of these plants are medium light though. Sure do wish I could find a PAR meter at a good price or rent one so that I could find out how much light my LED is putting out.

 

[dutchy]

Sounds good to me. Just watch your plants and adjust accordingly. No PAR meter can beat that. Slow growth can still be healthy growth.

I don't think it's very useful to keep switching the light every day. Just make sure the spread between them is ok. Light spreads in every direction.

 

[thegasman]

We'll I decided to go ahead and get a second Marineland Aquatic Plant LED. It was funny, my one week old HC literally took off yesterday after this post. Each group has several runners that have sprouted and it began to pearl a bit. I'm sure that it's a combination of slightly increased CO2 and flow, but obviously the LED is getting to the HC since it's growing out and not up. I'll let you know how things go in the next month.