T5HO lights

avraptorhal

I just received my dual T5HO light. My first reaction is WOW!!!. i had single T8 in a standard plastic hood. I have now replaced the hood with a glass canopy and the dual T5HO light. I can see the tank now without straining.

I know that a lot of the members are not in favor of T5HO bulbs, but I'll figure out what is happening.I'll post my reactions as I go. The tank is about 5 months old w/4 platys and Serpae Tetra. The tetra is a chaser if someone ventures in what he considers his territory.

DKRST

I use T5HOs exclusively and like them. However, they are usually overkill for a FW setup using a standard tank depth. I do have questions and cautions!
How many bulbs do you run? Some brands like Zoomed, allow you to use only one bulb.
What type (daylight, plant, actinic, etc)?
How far above the substrate is the light mounted?

1) More intensity is not necessarily better, long term.
2) The bulb will determine the intensity, to some degree. Plant bulbs are rather dim, tending to the red spectrum. Daylight bulbs give off higher PAR (photosynthetically active radiation), while actinic is waay to strong for freshwater!
3) The distance to substrate will seriously impact the intensity! Intensity decreases as a square function of the distance from the bulb. You really want a T5HO at least 20" minimum, depending on your setup, above the substrate. My dual fixture is suspended about 20" above the substrate, I'm using pressurized CO2, and occasionally still have algae issues!

Watch your duration/day also. Watch for BBA algae. It won't show up immediately, but if you have too much light intensity, it will show up.
You can reduce the light intensity by using fiberglass window screen across the tank top or on the splashguard of the light. Each layer cuts light by about 40%.

avraptorhal

I have 29 gal which is 18" deep bare tank. I have 1" to 3" substrate (one of my newbie mistakes). Hopefully, I'll luck out. It is well planted Anubia, Crypt, Water Wisteria, Swords, Java Fern. The substrate is combination of Flourite, Laterite, and gravel, mostly in layers

djembekah

how many watts and what's the color temp? i also have a T5HO on my 29 gallon. i dose extra ferts to keep the plants happy.

avraptorhal

I have 2 24w bulbs. 1 - 10000K 1-650 nm bulb. I intend to replace the 10000k W/ A6500k.They are on the legs that come with the fixture. I am in a rented apartment so I can't put any holes in the walls big enough to support the fixture. The legs look to put the fixture about 3" above the top of the tank. I finally got my fat butt out of the chair and measured it. The frame of the fixture is 2.5 inches above the tank, the lamps are recessed about another .5 inches

Now an observation after one week of operation, I don't understand what I'm seeing. The algae that had started to accumulate with the original single T8 bulb have started to reduce in density. If it is true, I have discovered a new treatment for algae LOL. I did add a single dose of Flourish Excel the same day that I installed the light. In the short time the T6 bulbs have been in the plants have started to look healthier, it could be wishful thinking.LOL

Geomancer

The Excel may have reduced the algae. It can also kill some plant species, and its long term affects on fish are not known. It is a rather nasty chemical though, something I would not be eager to use in a tank with fish. It does help with plant growth (for the plants it does not outright kill) but the risks are not something that's known as 'fact' at this point. If you look up the chemical at first glance it does not sound like something you would want anywhere near living creatures.

There is nothing wrong with T5HO, just as mentioned it raises the bar for balance and additional CO2 is for sure necessary, pressurized is likely the safest option.

DKRST

Glutaradehyde, the active ingredient in Excel, can be nasty in concentrated form. You are using about a 1.8% solution. That's pretty weak. I'm a biologist/professor and make up my own 1.5% glut solution from the 50% concentration stuff. When using the concentrate, I use protective gloves, a fume hood, and eye protection. Having said that, I use the diluted solution in some of my tanks at home and I don't worry a bit when I get it on my skin or about the fish when I use it. I just wash after using it. I used it daily at a 2x dose in my 55 gallon tank for over a year until I got a pressurized system and it works great! I'd use it again and I still use it for algae control.

Regarding Glutaraldehyde in general, here is my experience:
You probably will not see results within a single week, I'd say try it a month for a good test run. It's NOT exactly the same as CO2, this chemical increases growth up to about 4X normal, depending on light. Pressurized CO2 can increase plant growth up to 20X ! It's NOT a fertilizer, it adds to the available carbon for plant growth, think of it as similar to liquid CO2. You still will need to fertilize your tanks for best results and may need to fertilize more heavily than normal.

IMPORTANT NOTE: a few plants are sensitive to Excel and don't react well:
Vals, Elodea/Anacharis/(Egeria densa), Riccia, Mosses.
Sometimes these plants do well with the chemical, or die back and recover, sometimes they don't recover...
My Vals died back, regrew finally when I double-dosed, and then they grew great!
Plants that seem most sensitive are those that don't grow emersed at all, the true "aquatic-only" plants.

Ok, back to your light question.
Can you run only one bulb? If not, then I'd suggest using a layer, probably 2 of fiberglass window screen material. Each layer cuts the light by about 40%. With two bulbs you have probably more than twice the light you really need. Try using one layer of screening for about a month, see how it goes with plant growth and algae. If you dose excel daily, you can get away with slightly elevated light levels but make sure you dose Flourish comp 2x per week. If you start seeing algae issues, try 2 layers of screen.

It's all trial and error. Even the rippling of the tank's surfaced will impact the amount of light the substrate receives. Worst case, get some Frogbit and let it grow until it covers the water's surface. Then you can probably run both the bulbs, no screen and not get too much light!

Have fun with it and don't be afraid of using Excel.

DKRST

A single dose of Excel probably didn't clear your algae. Was it brown? If so, it was likely diatoms and they usually clear up on their own. All your plants should do ok (not positive about the Java Fern) with Excel added.

Make sure you use root tabs, particularly for the sword(s). I think all your plants will do well at lower than "bright" light light levels, and the anubia in particular needs lower lighting. Why? Because the anubia grows so slowly the leaves, even in medium lighting, tend to accumulate algae as they age. It really needs to be shaded under another plant and don't plant the rhizome in the substrate, it will rot. You can put the true roots into the substrate, but don't bury the really "fleshy" bottom part that the leaves attach to.

avraptorhal

Thanks a bunch! I was having trouble understanding Geomancer's post. I had been using Excel with the single T8 bulb and it seemed to be moderately useful. I also dosed Flourish Comprehensive according to the bottle directions. As I said in the original post I was amazed at the results of a single dose of Excel the day after the installation of the t5h0.

I didn't really believe that T5HO bulbs did anything re the algae. It was my poor attempt at humor.