They are green, slimy, and slippery. Many people consider them a nuisance on the lawn, patio (Tips on how to make a perfect patio), walkways, outdoor staircases, aquariums, swimming pools, among other places. But what are moss and algae, anyway, and why do they grow on unlikely places? According to the book “Lawn Care for Dummies”, the conditions that allow the growth of algae and moss are the combination of dampness, heavy shade, and poor air circulation. Other conditions include acid, infertile soil, poorly-drained soil, and areas with too much thatch. You may have noticed that these conditions are almost anywhere in the average household and garden. These plants can make your home look very untidy. Try peering at your roof because a lot of these plants grow on water spouts and roofs of any material, such as asphalt, cedar shakes, and concrete tile. If you neglect this, your roof may suffer from premature destruction. So grab your working gloves!

Problem Area # 1 : The Roof

Algae and moss on your roof look small but like a toilet sponge, and these absorb moisture four times their weight. It only takes a matter of time before your roof gets a heavy, moist covering that'll make it heavier each day. This unnecessary weight on your roof presses down on the rafters and sheathing, and it'll soon destroy your roof shingles. Now, here's what you can do to get rid of it:

There are special cleaning tools for this operation such as Moss B Ware (or any equivalent) that comes with a watering can. Before making your roof cleaning mixture, make sure you read the container's instructions carefully for your safety.

The mixture generally follows the three pounds per five gallons of water measurement. You may want to assess the degree of algae and moss accumulation. If you're dealing with many clusters, then this will be a painstaking job because you need to pay attention to each shingle.

Start dusting the ridges with a sulphate monohydrate powder. Don't panic, because there are commercial products available (in powder form). Just ask for assistance in your local home improvement shop. You use three pounds of these for every 600 square feet of surface.

Let the powder dissolve naturally from rain or mist. The powder will gradually spread on your roof and into the ridges, poisoning the moss and algae after about three to four weeks of wet weather.

Remove the dead algae and moss. You can sweep or hose it down. Pay attention to dead moss or algae that still clings to the roof. You have to remove all of them. Be sure to rinse your outdoor plants since they may be unintentionally powdered in the process.

Repeat this process annually so that you'll have a long-lasting roof.

Problem Area # 2 : Swimming Pools

Are you planning a pool party? You'll be the talk of the town --- in a negative way ---- if your guests spot greenish growth on the floor and walls of your swimming pool. Here's what you can do to prevent a social disaster. You need some “shock” to solve the algae problems inside your swimming pool, literally. Shock is a highly concentrated chlorine that comes in granules. These granules raise the chlorine level of your swimming pool. The increase in chlorine levels create a condition that's toxic for organic algae and moss. Here's how to do it.

Try first to remove a lot of algae or moss by brushing the walls and the floor. You have to do this first so that the time it takes to kill all the algae will be cut in half.

The ratio in using swimming pool shock is generally one pound per 10,000 gallons. For tough jobs, some increase the dosage to one pound per 7,500 gallons. When it comes to measurements, it's best to follow the manufacturer's dosage suggestions.

Make a solution by dissolving the chlorine pool shock using a bucket of water before pouring all of it in the swimming pool. Never add the water to the chemicals. It should always be the other way around.

You should allow the pool filter system to run while you add the chlorine shock. The filter system should run 24 hours until the remaining algae dies . Monitor your filter and backwash thoroughly if needed.

Let the chemicals do their work. You shouldn't use the swimming pool until all the algae is dead, and until the chlorine level of the pool is back to the safe range of 1-3 ppm.

You can add a second dose of chlorine shock if the pool water color is still “greenish” after 12-24 hours of filtering. Dead algae floats on the surface or sometimes sinks to the floor. You'll know they're dead if they're white or grayish.

When all the algae is dead, vacuum your pool.

Your pool filter will trap a lot of dead algae during this process. Remove all traces of dead algae from your filter so that algae won't return right away.

Problem Area # 3 : Fish Tanks

If you own an aquarium, algae is your number one bane. Algae is a sign that the water in your fish tank is healthy, but too much algae may rob your fish from precious nutrients. You clean it one day and it's back the next day. If you don't clean it, the tank becomes slimy and disgusting.

Buy a scrubbing pad from pet stores so that you can score algae away from the sides of the aquarium. Get the special aquarium srubbers because ordinary scouring pads contain chemicals that are harmful to your fish. Acrylic tanks have special scrubbing pads, as well.

Leave your mechanical filter running while scrubbing the algae from the sides of the tank. After some time, you'll see that most of the algae have been suctioned by the filter.

Let the filter do its work by letting it run for few minutes more. Change the filter pads.

To prevent algae from building up in the first place:

You can start by relocating your tank if it gets hit by too much sunlight. Algae need sunlight to grow and multiply. You can also place a timer on your aquarium lighting.

Don't overfeed your fish. Excess food rots and promotes algae growth.

Don't place too many fish in one tank. Fish waste also promotes algae growth.

Buy the Chinese algae eater. This is a small fish that feeds on algae. These fish will serve as your natural janitors.

Problem # 4: Garden And Other Areas

If you leave algae and moss unattended, they may result in the transformation of mini clusters that evetually grow into unsightly clumps. These plants can discolor any surface they grow on, leaving semi-permanent marks on flower pots, brick walls, and terraces. They pose as a safety threat to children and elderly people because they can make outdoor staircases and pathways too slippery for comfort. Algae produces green scum that transforms into an unsightly tough, black crust the moment it dries. Mosses form a mat of growth on soil that prevents healthy lawn grass from growing, making it the nightmare of manicured lawns. Controlling moss and algae in the garden doesn't require herbicides. You just have to manipulate certain things to make it difficult for them to survive.

It's best if you can invest in having the exterior of your home cleaned annually. Have a professional who can change the pH of your garden soil. You can also prune some trees because garden algae thrives in shady areas.

Have some time to rake and disturb the surface of garden soil so that you can control the spread of algae and moss.

Forget about bleach and water and all that scrubbing. Buy a product like Bayer Advanced 2-in-1 Moss and Algae Killer or any non-scrubbing product that does the same thing. This should be a moss, algae and lichen killer that you can apply on lawns, fences, staircases, or anywhere where there is algae or moss.

Follow these tips and your moss and algae will soon be gone. If not, consider that in Japanese gardening, moss and algae are an aesthetic element. The Japanese use these small plants to carpet a forest scene, adding a sense of stillness and calmness. In the average modern household, these small plants rarely bring beauty though, so you better start cleaning!