Discus, Plants, & MH Lights

Been reading your forums for some time. Very nice!

I want to keep a moderately (not sparsely planted, nor heavily planted) but moderately planted discus tank. Have done much research but still have two remaining questions.

First, I absolutely love and much prefer the look of MH lighting. More natural to my eye. I know most of the pros and cons of MH but don’t know the following. Would 2x175 just be too much for a standard 75gal to handle? Would the plants (because of high lighting, sufficient nutrients for health, and added co2, cause me/the plants to require a lot of extra maintenance. Would the growth rate be “out of control”, I am fine with and will strive for the moderately “wild” look (as opposed to the “Dutch” look,) and will use mostly slow growing plants. I don’t really want my plants to mimic Jack’s Beanstalk’s growth levels. Will 4+wpg turn my tank into a raging jungle?

If so………

Can I mitigate the amount of light down to say…. 2.5-3.0 wpg (still a lot of light......I know) by raising the MH up to say 15, or 18 inches or more above the tank, adding a glass top, and using the UV shield supplied with the MH Hood. If I do raise the hood that high, would, could this cause any other problems I haven’t thought about.

Secondly, will the discus be spooked (fearful and shy) of the lighting? I can always buy a 2x96 pc hood and not have to worry. It’s just that I don’t care about the extra cost, and I think that MH really gives the tank a more lively and natural look. (I know this is a “Beauty is in the eye of the beholder” kind of issue as others prefer PC, VHO or NO.)

Any insights or recommendations are greatly appreciated.

Poval.

[stygian7]

I use MH lighting on my tank (3-175watt over a 125 gal), and also much prefer the look of the MH. Initially, I had a major algae problem. Since, I have started following the Sears-Conlin recommendations for controlling algae with a marked improvement. Yes, your growth rate is likely to be high with that light level. Since getting my nutrients balanced, I have to trim weekly. I don't have enough experience to say with any certainty, but without some fast growing plants to pull the phosphorus out of the water, algae may be a constant battle.
Raising the light will decrease the light intensity in the water, but may cast a strange lighting around the room if your using anything higher than a 5000K lamp. Anything you put in between the lamp and the water will diminish the cool sparkling effect that the MH lamps generate. With that said, I do use the UV shield, not to block UV rays, but because I don't want a splash to shatter a lamp. As far as UV goes, unless your using HQI lamps, the outer globe will absorb the vast majority of UV radiation.
My fish got used to the light level pretty quickly. When I first started using the lamps, I had plastic plants. Almost instantly after switching to live plants, I noticed a significant change in the fish's demeanor. Their colors were brighter, and they didn't hide nearly as much. I guess with all the extra potential hiding spots, they felt safer.
Hope this helps,
-Kevin

Thank you Kevin

Very helpful info. Don't get me wrong, its not that I don't want to work to keep the tank healthy, just that I am disabled and trying to minimize the workload and still maintain a beautiful planted discus tank (mutually exclusive? ha ha). Building an auto water change because I can't lift buckets of water etc.

Will look into the Sears-Conlin algae thing as well

Poval

[ChloroPhil]

Poval,

You'll be just fine with the MH lighting and your fish will appreciate it more than a like amount of PC lighting.

There are plenty of choices of plants to use in a low-moderate maintainance tank and the size of your setup will allow some great looking Echinodorus. Not to mention the possibility of having this be open top, you could get some really cool emersed growth as well.

Best,
Phil

[rdeis]

[quote author=poval link=board=7;threadid=17154;start=0#msg176777 date=1079033814]
Secondly, will the discus be spooked (fearful and shy) of the lighting? [/quote]

I have read instances where Discus appeared uncomfortable because of the rippling patterns the light creates, but it doesn't seem to be a universal problem.

My "moonlight" creates shadows and ripples during the night cycle, and mine are always out comfortably playing in the light spots at night- shadows from ripples and other fish don't seem to bug them in the least-- and they've only been in the tank a couple of days!

I am using 2w/g PC in a mix of colors during the day cycle and no CO2. The discus don't seem to mind very bright light as long as there are shady spots to retreat to when they feel like doing so.

[captainandy]

I have 2-175W MH over a 90gal. I have about 25 different plants and they all do very well. Half hour after the lights go on, the plants begin to pour out bubble-trails of oxygen.

If you go with MH, go with the higher kelvin value. The 10,000K gives off a crisp blue-white hue that really brings out the brilliance of the colors of the discus. Lower wave lenghts appear somewhat yellow to red and are not as pleasing (IMO).