cleaning aquarium

Question
Hello and thank you in advance for your time and help.  I have had a 20 gallon tank for over a year and finally decided it was time to change it and clean it thoroughly rather than just adding new water.   I have small and normal fish.  I bought new stones and rinsed them well, cleaned the filtration system and replace the filter.  I saved some of the old water to be added to the new.  I conditioned the water before putting the fish back in (for about 4 hours).  Today is the 3rd day and the water is quite cloudy and unnerving.  Help?

Thank you,  Linda

Answer
Hi Linda,

What happened when you cleaned the aquarium, is you disrupted the beneficial bacteria that keep your aquarium stable. You interrupted "cycling" which is an essential concept to familiarize yourself with, so you can understand the basic chemistry behind fish keeping. Google the words cycling aquarium and you will get lots of results, you can also take a look at the following two sites, especially the first one:
http://www.firsttankguide.net
http://freshaquarium.about.com

I hope that this year, you weren't just topping off evaporated water, but that you did once in a while change the water - right? I heard someone at the fish store the other day tell the employee that he never changed water, just topped off! It's amazing that anyone can get away with this, but the secret I believe, is having water that is very hard, because water that is very hard (with a high pH, alkalinity and hardness) resists change and keeps itself very stable.

HOWEVER, it is necessary to change water, at the very least twice a month, preferably once a week, because changing the water dilutes the wastes your fish produce. Otherwise, they just sit in a pool of uneaten food and their body wastes! For your 20 gallon tank, it would be great if you could change 7-10 gallons a week but even 5 gallons would be ok. 10 gallons every two weeks would be the least amount of water you could change, do strive to change a bit more than this, and always use dechlorinator that removes chlorine and chloramine. Prime, by Seachem, comes in a 50 mL dropper bottle - just add 2 drops per gallon. Using a gravel vacuum will make changing water much easier.

Now, about your cloudiness. What you need to do now, is change water every day. It's a big pain, but your tank is "brand new again" - saving the water didn't help at all, because there is no beneficial bacteria in the water practically. I would say 98% of it is in the filter, more specifically the filter media. That is why I do not like those "cartridge type" filters, because every time you throw away one and replace with a new one, you discard lots of beneficial bacteria. Filters with bio-wheels are better than cartridge filters without bio-wheels because at least there is beneficial bacteria in the bio-wheel, but the best kind of filter, in my opinion is an AquaClear filter. For a hang-on back filter, an AquaClear filter can't be beat, because the foam sponges and Biomax bag of ceramic rings never needs to be discarded, just rinsed in water from the aquarium. Never rinse filter media in chlorinated tap water, this kills it, since chlorine kills both good and bad bacteria. Do look into the AquaClear filters.

You really ought to change 50% of the water daily because your cloudiness probably indicates you have ammonia and/or nitrite in the water. If you read about cycling, you'll see that these levels are toxic to your fish. Changing 50% of the water every day will be a big chore, but if you can do it, you'll protect your fish from getting ich, finrot, fungus, and all of those other diseases that fish get when they are in poor water quality. Change as much water as you can, always adding dechlorinator, and in a little while, it will clear.

If you have some aquarium salt (and no doubt you do, the pet stores love to sell you this repackaged sea salt or kosher salt!) you should dissolve it in a little hot water and add it to the aquarium, for your sized tank 4 tablespoons ought to do it. This is definitely more salt than you should ever add at once except in special situations like this, where you are trying to protect them from the effects of ammonia and nitrite. If you have an air pump with an airstone, make sure it is on full blast - when the water is unstable like this, fish need lots of aeration in order to recover from the stress of the toxicity.

One word of caution. I know you are probably very tempted to use "cloudy water removing" type potions. These things are actually useful when your water is full of particles, for example if you set up a brand new tank but you forgot to rinse the gravel so there's tons of dust in the water. What cloudy water removers do is bind together little particles to make them bigger, and therefore more able to be processed by your filter. They do NOT help whatsoever with a "bacterial bloom" which is what you are undergoing right now.

While your water is cloudy, you shouldn't feed the fish at all if you can help it, or at least feed very little. More food adds to the ammonia and nitrite in the water, and usually fish are not very hungry anyhow when the water is this way. So do those water changes, add that salt, hold back feeding - and eventually, all will be well again!

Next time you're at the pet store, look at the AquaClear filters and considering switching to that kind if it isn't what you're using now, it really is much more economical in the long run not to have to buy those cartridges. You can also just find AC media that fits in your filter and use it, I use AC media in all of my filters, AC or not.

I hope that helps, take care!
Nicole