Making a nice anchoring of rooted plants in a filled aquarium seems like a simple matter — except to those who have tried it without proper equipment. That is especially true when the sand is not as deep as it should be. Sticking them in by hand, water up to elbows, is never satisfactory.
Pushing the plants down is easy enough, but to make them stay, and to get the roots spread out and nicely covered is another matter.
One of the exasperating things about the job when working without tools is that while trying to anchor one plant, another gets knocked loose.
These troubles can be avoided by the simple expedient of using a pair of thin planting sticks, especially with a shallow notch cut in the ends. The edges of the ends should also be rubbed slightly smooth, so that they will not cut or bruise the plants in pressing against them.
The sticks should be about 3/8 x 3/8 inches, and from 12 to 20 inches long, according to the depth of the water. Simply grasp the plant between two sticks and press it into the sand to the desired depth. Now comes the important part. Hold the plant down with one stick and push the surrounding sand against the plant with the other. If there are roots sticking above the soil, treat them the same way. Push down with one stick and cover with the other.
Working in this way will not disturb any of the other plants, and a much better view of the whole scene can be had than by working only with the hands and arms.
Where a plant like Giant Sagittaria is extra buoyant, and the sand is not deep, it may be desirable to place a small stone or two next to the plant.
Some aquarists, use strips of thin lead wrapped around the plant just above the roots, when they tend to float. A small amount of lead does no appreciable harm to the water. Just follow the general tips of aquarium cycles.
However, with the use of planting sticks nearly all underwater plants can be nicely managed. They are particularly useful, when through some accident in a planted aquarium, a single plant has become partially or wholly dislodged. The repair is easily made.
The foregoing dimensions of the sticks need not be followed closely. The general idea is to have them thin, and yet broad enough in which to cut a notch that will be effective. A pair of rulers is better than nothing.
To partially repeat my first paragraph, many aquarists make the double mistake of having the sand both too deep and too fine in size of grains. Both of these factors increase the tendency of sand to turn black at the bottom. It should be only deep enough to safely hold down the roots, and be coarse like building sand, with grains not less than the size of a pin head. A limited depth of sand, while desirable, makes planting more tedious without the aid of planting sticks.