Zoo Med Aquasun t5 ho 24"

Hi...a friend is upgrading his tank and passed along an Aquasun 24" two bulb T5 HO fixture to me along with a versatop for the 29 gallon tank he passed along a few weeks ago. My question is this...tank dimensions are 30x12x18...is a 24" dual bulb Aquasun T5 HO going to be too much light for the tank if I only want low light plants and don't want to mess around with CO2? The fixture has on and off switches for each bulb so I can just run one light if that is all I need. The original fixture he gave me has a 24" T12 20w (1275 lumens) daylight bulb which seems to barely be enough to see the colors of the fish (elb). Should I just keep the fixture I have and save the T5 for potential future use or should I just use one bulb...or both? Feedback and advice greatly appreciated!

 

I just picked up the 30" version of this light fixture last week for my 37 gallon tank (30x12x22 deep). I'm running the 6500k and flora bulbs with low light plants. So far my plants are really liking the lighting and growing really well.

 

I would have loved a full 30" to cover the length of the tank...but when it is a free hand-me-down, I am not going to complain...lol. Do you run CO2 or just use fertilizers?

 

I am running a DIY CO2 but only did that for the fun of trying a DIY project with my son. I don't think it has that much of an effect since I haven't put in a defuser yet.

 

Just noticed you said 30" tank and 24" light fixture. You could hang the light as it has a system for doing that. It would also allow you to adjust how high above the tank you'd like it for lighting.

 

Can't hang anything from the ceiling...my only options would be placing it directly on the versatop or using the little peg legs that came with it an probably raise it 1 to 2 inches above the glass top.

 

Don't set the fixture on the glass. It generates too much heat.

You will have enough light to grow anything you want! But you will need ferts and CO2 to balance the light to avoid algae.

 

Laying it on the glass would make me nervous personally.
If adventerous, you could try to DIY a hanger for it by using some 1" metal tubing from something like Home Depot to make something like this (please excuse quick mockup from MS paint lol )

 

Don't set the fixture on the glass. It generates too much heat.

You will have enough light to grow anything you want! But you will need ferts and CO2 to balance the light to avoid algae.

Okay...so not on the glass...would it be okay to put it up on the "legs" it came with that raise it an inch or so off the glass?

And eeeeekkkkk! CO2 is exactly what I am trying to avoid needing. Sounds like I would be better off running one bulb or sticking with the T12 20w 24" that is already in the hood and just line it with aluminum foil to reflect more light back into the tank.

Edit: Maybe I could try swapping the T5 HO with the lfs for a 30" T5NO...might give me exactly the right lighting (although the lfs told me T5 NO lights were not made that well compared to T5 HO).

 

You can raise the fixture and run it for a short time w/ one bulb to avoid high light plants.

The less time you keep the light on, the less light the plants use. For example, my T5HO light only stays on 5 hours. If I ran it for 8-10 then my tank becomes high light.

If you raise the light, then you lower the intensity of the plants' "sun".

 

So running the light for less time can help dictate if it is high or low light? Excellent to know. The original T12 my friend passed along is on for about 12 hours a day right now...but if I swap it for the T5 HO, I could run it on one light for less time and avoid algae issues...I love this forum...so many good ideas and feedback! Thank you!

I definitely don't like how dI'm the tank looks right now but I may run the T12 for a few weeks and see what happens...and save the T5HO for later if I need it or, like I mentioned before...would it be worth trying to trade with the lfs for a T5 NO single light...kind of splitting the difference between the T12 and T5 HO?

 

The less time you keep the light on, the less light the plants use. For example, my T5HO light only stays on 5 hours. If I ran it for 8-10 then my tank becomes high light.

Respectfully psalm, I have never heard of a tank's lighting setup being determined by the number of hours the lights are on.

The light intensity (low, medium, high) is determined by the type/technology of light (CFL, T12, T8, T5 etc), the number of tubes, height of the tank, and the fixture's respective distance above the tank.

Hoppy's chart explains (defines) the type of setup you have based on the above factors -

The number of hours the lights are on determines the photo period. This is the period of time that plants can perform photosynthesis and grow, converting CO2 to O2, and utilising/feeding on the fertilisers in the tank. Too short a photo period, and you may get no growth, too long a photo period, and you can end up with an algae problem.

Hope that clarifies the two parts of the lighting equation.

EDIT: Another aspect is the spectrum, or Kelvin temperature, of the tubes. Most plants will grow well with a 5000 to 10000k tube. Typically, 6700k tubes are used, and on deeper tanks 10000k. Above 10000k, you start getting into a spectrum that many plants can't utilise, but algae can, and does.

 

Many plants that are considered low-light can do quite well with a shorter period of intense sunlight. The ferns between my garage and my neighbor's garage get a direct blast of sunlight for three hours or so, and they are growing just as spectacularly as the ones under the walnut tree (which get a more even amount of light over the day). These same ferns will get scorched if they get a full day's worth of direct sun.

In our tanks, there are two things that determine whether the light is working. First, are the plants growing and looking healthy? If they are, then the light is bright enough and yet isn't too bright for them (there is always a point where light is too bright for plants, and they will burn). Second, is there an algae problem? If there's a huge overgrowth of algae, then there's likely too much light in the tank.
I have a 10 gallon tank that's lit by a pair of oversized CFLs, which are about 2" from the water's surface. The tank is medium-lit at least. I only keep the light on for 6 hours of the day. The Christmas moss and anubias are both growing well, and the only algae in the tank is a colony of cladaphora that takes about six months to get to an unruly size. The walls are kept clear by a small handful of cherry shrimp, and nothing grows on the substrate or the driftwood in the tank.

So yes, the normal method of determining light level in aquaria is based on light output during an 8-10 hour light period, but this is far from the only way that lighting is determined in the wild.

Note: None of this means that a T5HO setup is necessary for a low-light tank. It's much more cost-efficient (and energy efficient) to get the minimum lighting you feel is necessary to show off your fish. Low-light plants are almost guaranteed to do well in any light that allows you to see the fish. I do like T8 or T5 (not HO) bulbs over T12, simply because they're more efficient and the light seems to be better quality.

 

Wow...so much feedback...but I slightly confused...

What I can tell is that the T5 HO with two bulbs will make the tank high light, which I do not want. I also know that I don't think or like the illumination the T12 20w casts on the the tank (1250 lumens, 6500k 24 inch). I will give the glass on the hood a good scrub and see if that helps. If not, I think a T5 NO 30" might be just what I need without using CO2. I will see if the lfs will make a trade or I can try to sell the T5 HO on craigslist for like $35 if I can and then buy a T5 NO if they are about the same price.

 

Yeah, lighting can be confusing, but it sounds like you've got the part that matters to your current tank.

If the hood has a lot of scale or algae, that will lower thee light output. Scale can be removed with vinegar. This may brighten things up quite a bit.

 

Amazing how much gunk came off the glass of the hood where the light fixture rests when I used vinegar (added a bit of baking soda for scratchless scrubbing). Still, the lighting seems abysmal. I went to the lfs and was chatting with them about the T5HO...one said sell it for $50 on craigslist, one said keep it and run a 10000k and a 6700k in it and I wouldn't need ferts or CO2 and a third said run one bulb at 6700k and just dose every day with Flourish Excel. Urg! Back to the land of lighting confusion...

 

The one who said you won't need CO2 with high-lighting is wrong. Too much light will cause an algae bloom, if there's not something in the tank using up the nitrates and phosphorous. To get your plants to use up those foods, you need to add CO2.

My suggestion is to hang on to the T5HO light, because you may want to run a high-light tank at some point. The question is, what to do with your current setup?
-First of all, how old is the bulb in the T12? What kind of tube is it? Maybe you just need to replace the tube with a new one. Also, is there a reflector in the hood, or is it just black plastic?
-You could run the light for less time. Of course, this means less viewing of your fish. However, if you want to go for it, it's going to take a bit of experimenting. Essentially, you're going to need to find the maximum amount of time that doesn't encourage a huge algae bloom.
-You could try running the setup with only one bulb. Depending on how the ballast works, this may not actually function. Some setups require both to be working. This will still likely be more light than you need, but will be more manageable. You could add Excel or a biological CO2 generator to help your plants use the light.
-If you've got some basic skill with electronics (and I do mean basic... I've done this, and I hate mucking around with electrical stuff), you could retrofit your current setup to use T8s or T5s, which offer a bit more light, and offer more directed light. I've found that this improves the old T12 setups a little bit. This requires buying a new ballast, and possibly new end caps for the tubes.
-Or you could sell the T5HO setup and purchase a new, lower-light hood.

 

To the best of my knowledge, my friend said the light was about 3 months old. I thought I mention the specs of it...my apologies if I forgot...T12 20w 24 inch 6500k 1250 lumens...and I am starting with 12 hours a day. There is a very basic white plastic reflector in the light strip which I am thinking I will line with aluminum foil to reflect better and I did as suggested and cleaned what scale I could off the hood glass with vinegar. The T5 HO does have on/off switches to run each tube independently so I may hold on to the fixture in case my plant growth is terrible with the T12...I can experiment with the T5HO.

 

Running just a single tube would put you around medium light with that T5HO fixture since it has independent switches. With a temperature of 6500-6700k tube.

There is a liquid source of CO2 like Excel. It's great for smaller tanks under 55g. All you do is poor into a cap and dump in the tank. Start with half dose. Quit simple.

Whatever you decide to do will be up to you. Planted tanks can be fun.

Best of luck with your decisions.

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