Aqueon 15W 18" T8: light too low

Nemo the Clownfish

Hi. My fluorescent tube (see title) is said by a reputable sorce to be at the low end of low on my 10 gal. planted tank. My original post was that the plants aren't growing. The lamp came with an Aqueon full cover.

I'm wondering if there is anything brighter (significantly) that I can put in that fixture. Maybe a brand-name tube would be brighter.

Apparently my 1.5 W/G is too low - I shoulld have at least 2 W/G or better. What do you think - especially 10Gers.

Thanks

Byron

I don't know who/what the "reputable source" might be, but I would only agree with respect to the type of tube; a single T8 is fine. I have had thriving planted 10g tanks with a single T8 tube in a good spectrum, and also (presently) with incandescant CFL bulbs. My fluorescent fixture gave out, so I replaced it with the less expensive incandescant since the CFL daylight bulbs are very good for the smaller planted tanks.

The Aqueon standard tubes that come with their hoods are poor, very low intensity and purplish. Measure the existing tube and then see if you can get a "daylight" with 6500K from a hardware-type store; if not, then you will have to go with the more expensive fish store brands, like Life-Glo or ZooMed Ultra Sun, in T8. Make sure you do not get T5 tubes, they will not work in a T8 fixture.

Byron.

Nemo the Clownfish

The reputable source is, well, you have the book. I'm confused. I got a few weeks of remarkable growth, trimmed the plants, and they all have since been dying a slow death. GH is 5, pH is 7.0, KH is 2, nitrates are 20 ppm, I think the tank generates about 5 ppm per week at this point.

Using Equilibrium in water change water and add .85 mg per week Flourish Comprehensive.

To get back to the tube, I can check out a nearby less-expensive hardware store but I'm prepared to buy a name brand tube. In the meantime, I've got an old dual T8 - haven't checked the wattage, but it's brighter. It's rather unsightly and hanges off the ends of the tank, but it's functioning. I'm real curious to see what happens in the tank with the light.

I'm very concerned, so i'd be grateful if you could tell me any problems there are in the specs I gave.

Thanks

Quantum

a different bulb may appear brighter, but will likely not produce significantly more mmol/m2/sec PAR (photon flux from your other thread) so will not necessarily be better for plant growth

Quantum

Some clarification; I agree and as I recommended in the other thread, that a more balanced light is better than the 8000K bulb (also from the other thread, I'm assuming yours is not the 8000K Aqueon bulb).But the point of my earlier post is that you shouldn't expect a bulb with a different spectral output in the same fixture with the same wattage to significantly change the light environment of your tank– it will not mean the difference between low light and high light, the PAR will be about the same.


The advice given in the other thread still applies, don't get too caught up in numbers and rely on the empirical data. As suggested here and the other thread, we know from experience and observation that your light is fine for many plants. I would explore other possibilities as to why your plants are not growing.

Byron

First off, to identify an issue and suggest how to resolve it requires all the data. What plant species, and how heavily stocked is the tank, and how frequent are water changes and how much. What is the temp, and how long is the light on daily?

Second, i will have to see this other thread that Quantum refers to, but off the top I do not agree that spectrum has no impact on intensity. I know after years of using the tubes that plants will grow much stronger under full spectrum lighting as opposed to these so-called plant or aquarium tubes, when they are in the same size/wattage. The Life-Glo, UltraSun, Daylight etc tubes give out more light than the Aqua-Glo, Flora-Glo, or the Aqueon thing. I could cite a number of plant authorities who say the same, so without knowing the technical reason the end result is what it is. I may have more after reading that other thread, if I can find it.

Byron.

Nemo the Clownfish

Plant Species (Common Name): Water Sprite (planted), Fanwort, Wisteria, 1 small Sword unidentified, 2 unidentified small crypts.

Stocking Level: medium

Water Changes: weekly 25%

Temperature: 78F

Photoperiod: 10 hours

I can't recall what the other thread is. Quantum: could you help?

The old fixture I'm currently using has daylight bulbs in it - length 24".

Mikaila31

How exactly are the plants dying? What are the symptoms?

1.5wpg is certainly enough light for plants in a 10 gallon. I would say you may have a nutrient deficiency. Thats usually what a sudden halt in growth points to when not much has changed.

Nemo the Clownfish

After trimming about 4" out of 11" high, most of the planted Water Sprite leaves turned brown, the Cabomba is losing leaves, some to near the top, but no degradation of the stems, and the Wisteria just stopped growing. Recently it put up some smooth-edged leaves (2 pairs) and since I put the double T8 on it has sprouted crenelated leaves.

The Sword is really dying slowly - I guess I was exaggerating about the other plants - they just stopped growing. The Sword has shed it's adult leaves over time and now it has some translucent spots on the biggest leaves. It has produced a baby plant which is putting up thinner, smaller leaves but I don't want to try to separate it.

GH from tap had been around 2 ppm so with a recommendation I started using Seachem Equilibrium leaving GH at 5 ppm, which should have helped things rather than hurt. I have a Flourish tab under the Sword, and administer Flourish Comprehensive at the recommended dose of .85 g. once per week.

Quantum

if the plants have been in the tank just a couple of weeks then that may be at least part of the answer, it takes a while for plants to settle in when moved to a new environment, some have been grown emersed and will lose those leaves and new ones (often of a somewhat different) form will grow in to replace them

also, cabomba and wisteria do need more light, how much more I'm not sure as I've never had these, but the others should do fine under the single 18" T8

the other thread I was refering to: Help With Calculating Light Intensity On 10 Gal.