In one sentence, describe what the following article is about: Use a pair of needle-nosed pliers, forceps, or even a wrench to grip one side of the knot itself (as opposed to its “arms”).  Hold onto the knot with your other hand or with a second pair of pliers.  Tug gently at the knot.  This is done to loosen up the knot.  Once it loosens, pull the knot apart with your hands. Do not pull as hard as possible or you might break the knotted material. Creating space within the knot will help loosen it. Depending on the nature of the knot, you could use a variety of tools for this. For small, tight knots, try using the fine teeth of a plastic comb or one tong of a fork. On larger knots, you might be able to use a bamboo skewer. Anything pointed and not too sharp will do.  Slip the implement of your choice into the knot.  Wiggle it back and forth a bit. Without removing the implement you worked into the knot, pull at one portion of the knot to see it if it comes apart. If the knot is still too tight to untie, wiggle the implement you placed in it a bit more, or take it out and try to push something with a slightly wider girth into the space you opened up.  Afterwards, try to untie it again. If you can place your knot on a hard, flat surface, you could attempt to untie it using a hard fist-sized rock or a hammer.  Start with a gentle but firm tap using moderate force.  After a few taps, test the knot to see if it can be untied.  If not, continue, adding force gradually each time you check the knot. Be sure that whatever is beneath the knot will not be damaged by the impact.
Summary: Take the knot apart with gripping instruments. Work something into the heart of the knot. Tap on the knot.

In one sentence, describe what the following article is about: In addition to monitoring and regulating ammonia levels, there are several things you can do to keep your aquarium healthy. Make it a habit to care for your tank water regularly. For example, you should check the water temperature every day.  On a weekly basis, replace 10% of the water with dechlorinated water.You should also test your water for nitrates and ammonia weekly. Each month, change 25% of your water. You should also perform any necessary filter maintenance. On a monthly basis, scrub the algae from your tank. Prune live plants if you have them. Write down your maintenance schedule on your calendar so that you keep track of each of your steps. Part of maintaining a healthy aquarium is to provide the proper amount of lighting. Most fish need 8-10 hours per day. Make sure that they are getting the correct amount of light.  You can purchase lights with timers for your aquarium. This will ensure that you are not over or under lighting them. Practice precaution after a power failure. Even a brief loss of power can cause stress for your fish. After a power outage, check to make sure that all of your equipment is functioning properly. In order to have healthy and happy fish, you need to provide them with the proper diet. What you feed them will depend on what type of fish you have. Make sure that you are purchasing the right food for your aquarium.  Make sure not to overfeed your fish. That can cause the tank to become contaminated. Experiment to find the right amount of food. Your fish should eat their fill in about 5 minutes. If it takes them longer than 5 minutes, reduce the amount. If they finish quickly, add more food. Try to feed the fish at the same time each day. Keeping to a schedule will help you keep track of feedings. An important part of keeping your fish healthy is to carefully control the population. When you are increasing the population, it is best to increase your number gradually. Do not add more than 3 fish at a time.  Purchase healthy fish. The best way to do this is to go to a reputable supplier. Read reviews from other customers. Make sure to acclimate new fish. Keep them in their bag for the first 15-20 minutes that they are in the aquarium. If you have had to medicate your fish, take extra precautions to keep the others healthy. Perform water changes more frequently to make sure you get rid of traces of the medication.
Summary:
Set up a water care schedule. Perform regular maintenance. Feed your fish properly. Create a healthy home for your fish.