Kill the algae before adding CYA. As long as your pH is somewhere between 7.2-7.8 you don't have to do anything. If it drops lower, raise it with some 20 Mule Team Borax. If it goes above 7.8, lower it with some muriatic acid. (Read the using muriatic acid link in Janet's signature.) Don't test your pH when your chlorine is above 5ppm or you'll get a false reading. After the algae is dead and the pool is cleared up, keeping the chlorine between 1-3 will work as long as your CYA is less than 10. However, as your CYA level rises, so does the needed chlorine level. (See the Best Guess Chlorine Chart in Jan's signature above.) You won't want to keep your CYA at less than 10, however, or else you're gonna have a hard time keeping chlorine in the pool especially on a hot sunny day. We suggest a CYA level of 40-50 for most pools.

Until you can get the good kit (and you should), you won't be able to test chlorine readings higher than 5ppm. But, you can force your kit to read higher by using a dilution method explained here: Testing Without a Good Kit

Hope this helps.