Plants starting to turn brown. I'm a noob at this, help!

[suprdave]

Newly-cycled aquarium. I have about 1 1/2 inches or so of just gravel, and a nicely planted aquarium of just various kinds of freshwater plants I picked up at Petco.

I am using a Flora-Glo 2800K "Freshwater plant growth aquarium bulb" for lighting.

At first the plants were thriving very well, especially the Cabombas. Nice and green, growing quickly for about a month. However recently I have noticed that they are starting to turn brown and leaves are falling off, especially on the Cabombas that used to grow like weeds. I have a feeling more than likely some sort of nutrients that were in the gravel and water originally have now been depleted, but I am having a hard time finding solid information on what I need to do.

Yesterday I purchased Tetra FloraPride and added it to the water, but obviously it has not been enough time to know if this is going to help or not. What else should I do to keep my plants happy?

 

[mfdrookie516]

What kind of fixture do you have (T8, T5, T5HO, etc)? How many watts? Just 1 bulb?

 

[suprdave]

T8, 20W. Just 1 bulb, it is just a 36 gallon bowfront.

 

[mfdrookie516]

I'd say that's your issue. That's very low lighting. I'd say with that lighting, you'll only be able to sustain some of the lowest light demanding plants like anubias, java fern, and java moss. In order to have those plants live/thrive, you're going to have to significantly increase your lighting.

It's generally recommended that bulbs be between 6500k and 10,000k for plants. That said, typically those plant bulbs have the correct spectrums for plants to thrive, so I doubt that's contributing to your issue.

 

[suprdave]

Sorry, a bit confused on that response. So it's not the Wattage I need to be concerned with, but color temperature?

It's kind of strange that this would be the issue, as the plants have been growing well for over a month before this started happening.

So, this is the bulb I should replace it with? LIFE-GLO 2 Fluorescent Bulbs by Hagan - Lighting & Hoods - Fish - PetSmart

The box states it's 6700K, 20W

 

[greenworld]

Try to get at least 60 watts if u gonna use T8. Use 6500k daylight bulb. It doesn't matter whether plant bulb or shop light. Buy cheap ones. That would be enough for low to medium light plants.

 

[mfdrookie516]

Sorry, a bit confused on that response. So it's not the Wattage I need to be concerned with, but color temperature?

It's kind of strange that this would be the issue, as the plants have been growing well for over a month before this started happening.

So, this is the bulb I should replace it with? LIFE-GLO 2 Fluorescent Bulbs by Hagan - Lighting & Hoods - Fish - PetSmart

The box states it's 6700K, 20W

No, sorry... it is the wattage. Wattage is far more important than color temp. What I meant by that is while 6500k-10,000k bulbs are generally recommended, those 2800k plant bulbs generally provide the necessary spectrums for plants (it's not the 'k' rating that matters, its the spectrum... I know, its confusing).

I would recommend upgrading to a T5HO fixture if anything. While the light you have will work for the lowest light demanding plants, you're going to be severely limited.