Things that can go wrong: Part 1

(Unedited version)
Originally appeared in the September 2005 issue of
Tropical Fish Hobbyist Magazine

I thought this month I'd try to go over some of the most common questions and problems you can encounter in a planted aquarium, and a few of the possible methods for curing them.

My Plants are Dying!

There are two main reasons that your aquarium plants may have die-off or poor growth; not enough light or the wrong plants.


You must have good lighting to grow plants. All plants need light to grow. But not all plants will grow well in the same light. A few plants can grow well in very poor lighting, but if you really want a good chance to be successful wiht a planted aquarium, you must have good light!

Plants need light for growth. It's amazing how many people will buy every fertilizer in the shop and wonder why their plants aren't growing while they use the hood with 2 incandescent bulbs that came with their aquarium. These will not grow very many aquarium plants. You can sometimes grow Java moss or Amazon swords in these lights but not much else.

A few plants will grow with a single standard hood with a florescent bulb

The easiest way to get good lighting on your aquarium is with florescent lights. There are other types of lights, there are a few that may be better but these are the easiest, most moderate cost and work just great. You can purchase a florescent hood for your aquarium in most any pet store. There are even newer lights becoming more readily available that have multiple florescent and compact florescent bulbs so you can really give your tank some strong lighting.

As to how much light you need it really depends a lot on what you want to grow, how fast you want it to grow, how many supplements like CO2 and fertilizers you're going to put in and how deep the tank is. On a 10 gallon tank you can grow plants like moss, some crypts, hornwort, Rotala indica, and maybe a few other low light plants with the standard single florescent 15 watt bulb that comes in the hoods for that size of tank. If you get the light strips and a glass cover, you can put 2 on a 10 gallon tank and grow a lot more plants. For a larger tank like a 50 that's much deeper, you really need more lighting to get it down to the bottom. Two 4 foot light strips on these tanks are really needed for moderate growth. On my tanks of this size I use 2 double light fixtures. The 4 foot lights are 40 watts so that's a total of 160 watts to get really good plant growth in these larger deeper tank.

When you get your florescent light bulbs there are many options. If you have one or just a few tanks I would spend the extra few dollars and get lights specifically made for growing aquarium plants. If you need a bulb and can't get an aquarium one it's perfectly all right to use a cool white or daylight type. I would steer clear of economy lower wattage bulbs on your aquariums; you're looking for more not less light.

Florescent bulbs wear out so if you had good growth for a long time then it slowed down you may need to change your bulbs. The bulbs can start to get less bright after about 6 months and many aquatic gardeners change their bulbs on a regular schedule, long before they may totally go dark.

Plant Choices

You have to be an educated shopper when buying aquarium. I often go in to aquarium and fish stores and see terrestrial plants being sold for the aquarium. These plants will languish in your tank for a short time and slowly rot away. Many of these are very common house plants like "parlor palms" and "pathos." Avoid these plants. You really need to have a good guide book or be sure your local store employees know what they're selling. If you aren't sure look the plant up before you purchase it.

Another practice that will bring about a similar sort of phenomena with a much happier prospective ending is the growing of plants intended for the aquarium, out of the water. Many aquarium plants grow naturally along the waters edge with their roots in the water most of the time and the leaves out of the water much of the time. This type of growth is called emersed. Nurseries usually grow the plants in the same way. This way the grower doesn't have to worry about snails and algae on the plants. This practice works great for the growers, and insures a cleaner plant will come to you.

The Echinodorus tenellus on the left was grown emersed and recently placed in the aquarium. The one on the right is the same species grown in the aquarium.

The bad part is the leaves that are grown out of the water will usually eventually die off after being put under water and new leaves must grow that are able to handle the different conditions of submerged life. Plants grow leaves to best suit the place they're living in. What we see are different shapes, sizes and/or colors in new leaf growth as the plant makes structural changes to be able to live under the water.

If your new plants are growing, and it seems the only dead leaves are those that were on the plant when you bought it, then don't worry about the old growth dying off. You will need to be sure to clean out the dead parts so you don't have a bunch of dead plant matter in your tank. More water changes at this time should help your tank clean and encourage new growth.

Finally some plants are just harder to grow than others. Be sure to start with plants that have a reputation for easy growth and that are suitable for the water you plan to grow them in. Like fish some plants are very easy and will grow in almost any type of conditions, other plants require high lighting, extra fertilizers and CO2 to survive. Choose plants that are suitable for your set-up and water. Just like fish, if you buy plants you haven't researched you may be in for a disappointment.

My Plants Stopped Growing

This is usually less of a problem but it does happen. If your plants are growing along just great and then they just seem to stop growing or at least slow way down, then you probably have run out of a nutrient they need. Some plants can be more sensitive about their needs than others. So even though some may stop growing others may continue to grow at the same time. This is a relatively easy problem to fix. First of all make sure you're doing regular water changes. I generally don't use extra fertilizers in my tanks, because I have good growth without them, but I do notice that my Glossostigma grows like crazy for about a week after I do a water change and then slows way down.

If you need to use fertilizers be sure to dose the tank at the recommended levels regularly so the nutrients will be replaced as the plants use them. If the plants slow way down between doses and water changes you will need to add more fertilizers and do more water changes.

Remember it might be your lighting. If you've had good growth that slows while your regular maintenance has stayed the same, and you haven't changed your bulbs in more than 6 months, it could just be that your bulbs have lost enough power to not provide your plants with enough light.

Also keep in mind you don't always need super accelerated growth. You may even find that as your plants continue to thrive you wish they would stop growing so fast so you could keep up with the trimming.

My Snails are Taking Over

This is a common occurrence, particularly in new tanks. There are several kinds of snails you can get into your tank, some whether you want them there or not. The larger snails like apple snails are more difficult to breed and generally considered desirable. It's the small snails that can become a problem. Malayan livebearing snails, ramshorn snails and common pond snails are the little trouble makers. These snails can breed quickly and easily get out of control in your aquarium.

With the small snails you have to decide if you want them for their beneficial uses with their population problems, or you need to try to keep them out of your tanks all together. There isn't much of a middle road with these snails. Personally I live with the snails. They are sometimes annoying but they do a great job on keeping some types of algae under control and eat up left over food and dying plant matter. The Malayan snails also spend a great deal of time cleaning through tank gravel keeping it cleaner and more aerated.

If you decide you don't want snails, but they've already found you, there are several ways to get rid of them.

Manually removing snails can be a nuisance and I don't think very effective in the long run, though it can greatly reduce the population if you're diligent at it. Do not put snails you remove in a natural body of water or your sewer! They can find their way back into the environment and wreak havoc.

You can often entice a large group of snails with food. Place food pellets or a small piece of seafood on a small glass or ceramic plate on the bottom of your tank. Snails will come to have the snack and once the plate has a lot of them on it, you can just take the plate out, clean off the snails, put more food on it, and wait for the next mob to fill the plate.

Another great way to get rid of snails is with fish. There are several fish that are very suitable for the job. Loaches in the genus Botia are the most popular and well known snail eaters for the planted tank. They come in a variety of colors and sizes. The most common is the clown loach, but consider well before you choose this fish for your tank as they can get rather large, some being reported at over 12 inches. Some of the other loaches remain smaller and have different color patterns. They also have a very interesting habit of communicating with each other through a clicking noise.

Another fish that's gaining a lot of recent attention is the dwarf puffer. These neat little fish look like their larger more aggressive cousins but stay very small. You will need to feed them in addition to their snail eating. They need a regular varied live food diet to thrive.

Next Time:Algae

Algae is of course one of the largest problems with the planted aquarium. It's such a big problem that it will require a whole column to explain how to curb it. In "Things That Can Go Wrong: Part 2," I will take a look at the problem of algae, and let you know some of the best ways to keep it from ruining your aquarium.

Questions or Comments?

If you have questions or Comments about this column, join the Natural Aquariums Forum and post them here.

Welcome to the Jungle | Into The Forest | The Creepy Crawlies | A Clearing in the Thicket | Algae Eaters for the Planted Aquarium
North American Natives | Why things go wrong Pt 1 | Why things go wrong Pt 2 (Algae) | Algae Eating Shrimp | Lo-Tech Tanks
Welcome to the Fish Room | The Stemmed Plants | Mosses | A Livebearer Biotope | Planted Tank Social | The Genus Hygrophila | Cyanobacteria
Easy Plants | What I Did Last Summer | Decorations in the Planted Tank | Botany-An Introduction to Plant Biology | Botany-Anatomy of a plant
Botany-How Plants Work | Easy Rosettes | Going High-Tech | Floating Plants | Dealing with Success | Bringing the Outside In | Vallisneria
Hair Algae | Flowering Aquarium Plants Part 1 | Flowering Aquarium Plants Part 2 | Liverworts in the Aquarium | Elements of Design
Planted Aquarium Maintenance | More Mosses | Invaders | Ferns in the Aquarium | Setting up a Planted Aquarium
Seaweeds of the Pacific Northwest | Proserpinaca | Hardware for the Planted Aquarium | Rotala | Neocaridina Shrimp | Lo-tech Tank Tips

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