[JordanW]

Hello everyone,

I've had a small planted tank for a year (my first aquarium) and am having serious issues with poor plant growth. An experienced friend helped me get set up, but we are both flummoxed about what might be going on.

Here are some details (I am still an aquarium newbie so please forgive the imperfect language or extraneous details):

• The tank is 5 gal, with the AquaClear 20 three-component filter system (foam + activated carbon + BioMax) running continually on low and filter components changed according to the manufacturer's schedule. No bubbler.
• I have a basic white fluorescent light (sized to the aquarium lid, and bought from a local aquarium supply store) in the lid of the tank. I can't remember the wattage. I have the light set to be on about 8 hrs / day
• I have a thermostatted 25 W heater and keep the tank consistently at 25.5 C.
• I do water changes every two weeks, as follows: I remove about half of the water in the tank and replace it with local tap water that I've left standing for at least a day (after adjusting the temperature with boiling water).

In setting up the tank about a year ago, I did the following:

• About 1.5 inches of Aquasoil on the bottom of the tank
• I planted the tank with a mixture of plants I had purchased: some Hydrocotyle, Bacopa caroliniana, Helanthium tenellum, Rotala wallichii, and "Pearl Weed". I also have some small colourful pebbles (from local lakes, but thoroughly cleaned first) added to the tank for decoration, as well as a "castle".
• Over time I slowly introduced small fish, two at a time -- guppies and neon tetras. I haven't ever had more than 7-8 fish at any one time. The tetras have mostly been consistent but we've gone through a number of guppies.
• We had a lot of small snails over about the first six months or so, which I removed as much as possible during water changes; I then got an Assassin snail, which took care of the other snails, and is still hanging around.
• For the past six months or so, I've been adding Flourish Excel every two weeks according to the manufacturer's instructions.

I had expected some decent plant growth, and for a while some of the plants did well, but things slowed down and then over the last few months especially a lot of the plants have withered or died completely. The only thing that really survived was the Helanthium, which has formed a nice green layer in one area of the tank. The Rotala grew and got quite bushy over about eight months, but then the leaves started to fall off and I cut the stems back (new growth has now appeared). The Bacopa also survived about six or seven months and then lost all its leaves. I have one surviving Hydrocotyle plant as well.

I've had some consistent algae problems on the walls of the tank, and try to scrub it off gently with a clean sponge during water changes. In addition to the general withering and leaf loss in plants, I have lately also noticed a thin gray hair-like substance growing on a lot of my plants, which I would guess is some kind of fungus.

Overall the tank looks very sparse now, and not very interesting to look at -- and although I am an aquarium newbie, I really expected more than this. I was hoping for something lush and visually interesting for us and the fish.

The change in the plant growth didn't happen suddenly (more like something I noticed over months) and so I can't correlate it to any one change that I've made.

I would appreciate any advice, or if anything that I've mentioned stands out as a "red flag" potential cause of problems, and any solutions that can be recommended. I can try to add pictures if that would be helpful. Thanks in advance.

 

[minorhero]

What you're describing is pretty much the classic case of adding aqua soil but never adding any other fertilizer. for a little while your plants will do great absorbing a nutrients from the aqua soil, but then those nutrients run out and the plants slowly die unable to find nutrients. You definitely should add a complete fertilizer on a regular basis. There are many options for this including all in one options as well as multi-part systems. I like nicolg thrive, because it's very easy all in one system that you just need to add once a week. It does require a 50% water change each week though. My advice is to pick a fertilizing system and follow the directions for it.

 

[JordanW]

What you're describing is pretty much the classic case of adding aqua soil but never adding any other fertilizer.

Thanks for your comment -- I would have thought that the fish waste would provide fertilizing action. I guess I need more. I will order the product you recommended.

 

[stelaro]

Very rewarding, I have learned many things