Originally Posted by higherme
so the only way to get rid of the hair algae right now is to remove by hand? But there are a lot sticking to the java moss. its hard to separate from the java moss without throwing some java moss away....
If i do 50% water change per week, will that affect my fish?
Java moss being the fine filamentous plant that grows on wood and rocks (as opposed to Java fern which is the dark green longish-leaved plant that also grows by attaching the "roots" to wood and rock) is so delicate it would have to be discarded if it is covered by hair/brush algae. You must really have the algae; I've known it to appear usually on wood and rocks and then more slowly on plants, some more than others (Anubias I read is particularly prone to brush algae).
The more water changes the better. Discus keepers often change 50% of the discus tank water every day. Most aquarists would find that a challenge, and the important thing is to stick to the routine, so it should be one you can manage. I do 40-50% of my 70g and 90g tanks every week. I can always see the difference, and I mean in the fish behaviour more than tank appearance. So yes it will affect your fish--but in a most positive way. It may be useful to explain why.
In nature, fish live in water that is either constantly moving past them (streams, rivers, creeks) or in a lake that has considerably more volume that will be affected by the fish population. In both cases, the water around them is not static but changing, which means the toxins the fish expel (ammonia through respiration, excrement, urine) is not staying where the fish is forced to live in it, but moving away. At the same time, the water is bringing minerals and oxygen to the fish, and there is no danger of the fish using all the available minerals or oxygen because of the water movement. There is a gas exchange at the water surface, where CO2 is given off and oxygen is absorbed. In a lake the thermal currents constantly keep the water in motion to avoid stratification. The African rift lakes are a good illustration. They are so deep that the lower water strata never mixes with the upper surface water. It is no surprise therefore that the cichlids do not live in the lower levels which are devoid of oxygen. They would in fact asphyxiate if they moved into those regions.
The aim is to maintain consistent water quality permanently in your aquarium. This is not as impossible as some may think. There are fluctuations that occur naturally, in nature and in our aquariums. Fish have evolved to adapt to these minor fluctuations. This involves temperature and pH (there are diurnal fluctuations in temp and pH both in nature and in an aquarium), hardness, and dissolved organics in the water. Fish are very closely tied to their environment. As an example, fish take in water through their cells by osmosis. The fish must adjust its internal pH to equal that of the water passing into its cells in order to maintain its physiological equilibrium--that is, the complex chain of internal chemical reactions that keep the pH of its blood steady, its tissues fed, and its immune system functioning. When pH and/or salinity stray outside the ideal range for any given species, or fluctuate more than minimally, the fishes' bodies must work harder and use more energy to maintain this equilibrium. Having fluctuating water conditions means the fish is constantly having to adjust its metabolism, and this stresses the fish and can lead to poor health, disease, and even death if not corrected. The point of regular water changes is establishing an equilibrium in the tank and therefore in the fish, resulting in healthier and happier fish.
As explained above, the replacement water cannot be significantly different from the tank water in terms of pH and hardness. If it is, it could be a shock to the fish and therefore be stressful, causing other problems. A small variation in water chemistry and temperature is OK as the waters mix and particularly a 1-2 degree drop in temperature stimulates the fish (often into spawning) because this replicates the effect of rainstorms in the tropics. But the larger the amount of the water change, the closer the water parameters should be.