why does my fish tank still smell?

Question

i cleaned my fish tank the other day, its a fresh water tank, and it is starting to smell for some reason and i cant figure it out. it is still extremely clean but the smell is not so good. when i cleaned it i did a full water change and everything. its a 29 gallon tank, with 2 water filters both work fine and have fresh filters. any suggestions im lost.

the tank is not anywhere near sunlight and when i cleaned the tank i cleaned out the entire filter units too. the filter units are fairly new as well. is there a carbon rock i can throw in there or liquid i can try for odor? also the fish are not over fed by any means so there is not much debree. and i have 1pleco and 4 corys to be maitaining the tank.

Answer 1

Your tank smells because you tore it all down and cleaned it all out! You effectively killed off all the beneficial bacteria that have been helping keep it clean and smelling good since it was set up. The smell and cloudiness is a natural part of the cycling in of a new tank. They go away on their own once the nitrogen cycle is complete.

You can help with the odor by doing partial (30%) water changes every 3rd or 4th day and putting fresh carbon in your filter.

Never, ever do that once a tank is up and running. Only do regular (weekly) partial (25-30%) water changes to keep the ammonia, nitrites and nitrate levels at or near 0. I have tanks that have been set up for years that have never been torn down. They are all healthy and happy and smell like fresh water.

The only time you should do a tear down is if a terrible disease wipes out all your fish. Then you would do a bleach clean to kill all of the parasites or disease bacteria in the tank so they will not infect the new fish you get.

I have a hospital tank that I use for a holding tank for new fish. If they are infected with something, I try to cure it with meds. If unsuccessful, I do a 100% teardown and bleach clean. Then, I refill it with water from other tanks (seasoned) and put a filter from another tank in it, let it run for a week and then add some guppies to see if it is OK.

Answer 2

Well #1 you shouldn't ever do a 100% water change. This tends to kill off the bacteria that breaks down ammonia. This is what you should do.

1)Get a cheap gravel vacuum and vacuum the gravel weekly, and replace 10-20% of your water. If it's smelly other than a musty/earthy scent do 20% changes via the gravel vacuum every day.

2)Don't over feed fish should be fed once a day only what they can eat in a minute or 2. If you worry about the cory cats, and pelco getting enough food. Buy sinking catfish pellets, and algae disks. The amount of food put into the tank is the only measure of the amount of ammonia produced. It doesn't matter if cats eat it or it rots. (Note that rotting food is bad for other health reasons.)

3)Don't change the filters at the same time. Changing the filter removes the bacteria living there, and these bacteria convert ammonia. Ideally alternate changing one every 2-3 weeks. Also take a spoon or knife and scrap some of the gunk on the filter media onto your new filter media.

PS- You shoud test your water for ammonia, and nitrates.

Answer 3

The stuff that lives on your rocks is essential in keeping your tank healthy. Beneficial bacteria digests fish waste (ammonia) and converts it into nitrites. Other bacteria converts nitrites into less harmful nitrates. This cycle tanks time to develop and your mucking with the tank just sickens the fish. Be a bit more patient and it will develop. Feed a lot less food, and change 25% of the water weekly (use a gravel vacuum) and make sure the temp of the new water is the same as the tank. You don't want to destroy too many of the beneficial bacteria when you do a water change and changing too much water or having it at the wrong temp stresses them. Also, your filter media has a lot of the bacteria growing on it. Don't change it too often (and never at the same time as a water change). When it start becoming clogged, rinse it out in cool tap water. Only change it when rinsing no longer is effective.
Remember, without this bacteria, your tank cannot break down excess fish waste and food, making the water smelly and polluted. It can take three weeks for your tank to clear up, but it will (if it doesn't, you are feeding way too much).
A

Answer 4

So what does it smell like?
Earthy?
Rotten eggs?

How deep is your gravel?

How long has it been since you'd had fresh carbon in the tank?

How often do you do partial water changes, and do you vacuum at each partial water change? How much water do you change out?

How many fish and how large are they?

How long has the tank been set up?

If you still have your old filter pads, rinse them well in discarded tank water. You don't want to throw those away. You do want to use those as long as possible. Rinse them each time you do a partial water change in discarded tank water to remove any debris. Smack them against something if they start getting stopped up. Many of the bacteria that keep your water happy (convert ammonia which is toxic to nitrAte which is less toxic live on your filter pads).

Here's a good article on what happens in a new tank
http://thegab.org/Articles/WaterQualityCycling.html

Here's a tropical tank/fish caresheet that may also help:
http://thegab.org/Articles/TropicalBasics.html

Answer 5

First, full water changes are never good for your tank, you risk eliminating huge portions of your beneficial bacteria and significantly altering your water parameters. Thoroughly cleaning your filters with untreated water can cause your tank to re-cycle.

The root of the problem is probably excess dissolved organics (and indicator of overfeeding and an inadequate maintanence).

To solve the SYMPTHOMS:

a. increase the amount of chemical filtration (carbon, purigen, chem-pure, etc) being used.

To solve the ROOT OF THE PROBLEM:

a. reduce the amount and frequency you currently feed (feed only half as much as you usually do and only once a day).

b cut down on tank lighting if more than 12hrs in duration.

c. Conduct water changes weekly (25%-33%) and use a gravel vacuum device to physically removed trapped waste products. Keep nitrates below 40ppm.

d. Upgrade your filters and overfiltrate. Equip your 29-gal with TWO filters configured for 55gal tanks. Clean/maintain them on alternating schedules.

Answer 6

Is it possible that your water supply is contaminated only to the point where there are more of one chemical than the other ones ? Sometimes water will smell sulphurish coming from well water. Either that or just try a new undergravel filter system and clean the old one out completely.

Answer 7

10% would no longer be a large adequate water replace for a goldfish tank. those are a messy fish and so a 25-30% replace would probable be better outfitted to tank upkeep. contained in the recommend time you want to do the water alterations another day or so till you get the tank chemistry again below administration.

Answer 8

Do you use that liquid water purifyer stuff? Or the salt rocks?? I had a betta and I used those two thing and it smelled really bad... Also fresh plants make it smell too. He was in just a vase, not a tank with running water or anything though.

Emily

Answer 9

dont do a full water change this imbalences the tanks water quality. only do small water changes 50%max once every wek or two.
is the tank in direct sunlight this may make the water smell. also make sure your not giving the fish too much food as loftover food will make the tank smell.

Answer 10

Try cleaning the whole filter unit out. Sometimes, algae witll build up in the filter itself. It can hide way down by the rotor that turns the pump. Good luck