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Category: Pet
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How do I treat cloudy gold fish tank

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I have just bought three fish for my son's 16 gallon tank: a koi, a tiger shark, and a fancy goldfish. We've had them for 2 days and the water has turned cloudy. We have a tetra bio-bag filter. I'm concerned about the cloudiness, whether our tank is too small for these fish, and whether I should be feeding the koi/goldfish pellets to the tiger shark. As to the cloudiness, I'm planning to change the filter cartridge and change about 20% of the water every three days or so. What do you advise?
Hi Vickie. Your son's tank is passing through what is known as the cycling process. The cloudiness you are seeing is a bacterial bloom.

I have listed below a link to a page that will explain cycling. Please read it and get back to me. I will elaborate further.
Customer: replied 10 years ago.
OK, that's helpful. Probably should have waited to introduce fish.
Vicki please hold on while I type a detailed answer.
Customer: replied 10 years ago.
Reply to TROPICAL FISH AFICIANADO's Post: OK. I appreciate any guidance, tips to help the fish make it through the transition.
Hi again. You're taking action at this early point in time probably saved the lives of your son's fish.

Just to put things in simple terms:
Uneaten food and fish waste produce ammonia which is lethal to fish. After about a week and 1/2-2 weeks the ammonia begins to get eaten by a bacteria called nitrite which is also lethal but not as lethal as ammonia.

At this point the ammonia disappears and the nitrites rise. After a few weeks the nitrites get eaten by a bacteria called nitrates (notice the a in nitrates). Nitrates in low amounts are ok and most aquariums have it. Once your tank has -0- ammonia and nitrites then it is considered to be cycled and one can begin enjoying their fish tank instead of fearing what's going to happen.

The cycling process on the average takes about 6 weeks but could last longer.

Ok, so how to deal with it, cycling. The first thing to do is test the water every 2-3 days for the presence of ammonia and nitrites. You can either do the testing yourself with a standard water testing kit which uses colors to denote amounts or you can bring a sample to most pet shops where they ususally will test for free.
I suggest that because you'll be testing a lot it's better to buy a test kit and do it yourself.

When you see ammonia or nitrites begin to rise or you see your fish acting sickly then you should change 30% of the water in the tank using a dechlorinator (something to take out the chlorine in municipal tap water) and same temperature water.

During this time of cycling it's advisable to cut down significantly on feeding the fish, as mentioned earlier, uneaten food and subsequent fish waste contribute to the ammonia/nitrite problem. Feed the fish every other day and only a very small amount.

Also do not change the filter media during the cycling as it's a very important spawning ground for the benefical bacteria. By the way your choice of filter. the Tetra, was a very good one.
I believe the Tetra filter comes equipped with a sponge or mesh that comes after the filter media in the filter. If so, do not rinse or clean that either.

On a final note. that was a very nice gesture on your part, to buy a fish tank for your son.
You did an excellent thing by investigating and acting on the cloudy water issue as many folks who also have newly set-up tanks do not do their homework and subsequently wind up with a disaster in their fish tank.

Let me know if you have any questions on anything I've written above and I'll be more than glad to help. Good luck and let me know if further assistance is needed during this most difficult and trying period in the life of an aquarium.
Customer: replied 10 years ago.
Thanks, Ric. Will the water testing kit make clear when dangerous levels of ammonia and nitrates are present? Should I treat the fresh tap water after I put it in the aquarium or before? And the fish will survive on getting fed every other day for a month? And finally, do you think a 16-gallon tank is too small for a koi, goldfish and tiger shark (and algae eater). Will the tiger shark do OK with goldfish food?

Thank again for your excellent help. I'll "accept" after I send this reply.

Hi Vicki. The test kits will give you a reading, for example .25, .50 etc etc. The only thing to remember is that any trace of ammonia is bad and lethal. With nitrites you can let them rise to the first bar on the test kit or strip. Don't worry if you have any trouble with the testing I'll be glad to assist. Just keep in mind they're color coded.

As far as treating the tap water I would say it's best to treat before putting it into the tank although many fishkeepers put it in after I don't favor the idea of exposing the fish to any risks of chlorine/chlorimine.

No need to worry about feeding the fish every other day as in the wild they sometimes do not eat/find food for a week.

Concerning your tank size, yes I do believe it's overcrowded simply because of the fact that the koi and goldfish will both get much bigger. The koi might grow to be 12". But right now it's better to just concentrate on the cycling process as what's done is done regarding the stocking of fish. Later on you can think about getting a bigger aquarium.

As for the goldfish food, to keep things simple, for now stick with feeding it to all the fish as I wouldn't want you to get preoccupied with different types of food and diet. Once the cycling process has ended you can think about the various dietary needs of each fish.

Hope this information helps and please don't hesitate contacting me in the future.
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