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I changed the water in my tank today and now my fish are at the top of the tank almost like they're gasping for air...what's wrong?!

well we need to know a little more than that

what type of fish? did you do a 100% water change or a partial one? did you use a chemical to remove chlorine? what is the water temp? did the container you used to change water with ever contain any soap or detergent?

I have two cichlids, i only did a 30% water change, temp is prbably a little cooler. Yes I used a conditioner maybe too much?

Jillieillie...

Are they still behaving abnormally? Other than the gasping for air, are there any other visible signs of something being wrong with the fish?

Gasping for air can mean a couple of different things. Are they getting enough oxygen, are you aerating the water at all by using an airstone or something else? If not, you may want to do so.

The temp. You mention the temp may may have been alittle cooler, what is the temp of the tank and how much cooler was the water you were adding to the tank at the time of the water change?

Is this a fully cycled tank?

What kind of Cichlids are these? What size of tank? What kind of filtration are you using? What kind of conditioner did you use? Are the fish eating?

It would greatly help to know what conditioner you were using. AmQuel Plus (and I guess Prime and Ammo-Lock too, and other similar products) will reduce the oxygen levels in the water for a while. Overdosing with those products will cause no other harm to your fish except of the temporary lack of oxygen. If you feel that is the case, increase aeration (another air pump, if possible) and surface agitation (direct filter outlet to the surface of the water), and add activated carbon to your filter (if not present) to absorb the left overs of the conditioner.

Another option might be that you've changed a little bit too much of the water and killed some of your nitrifying bacteria and as a result the levels of ammonia and/or nitrites have gone up. This can only be confirmed by testing. If that is the case, add one of the above products (AmQuel+ and Prime are better as Ammo-Lock doesn't claim to remove nitrites) and do small (10%) daily water changes until ammonia and nitrites are 0ppm.

I woke up this morning and everything was back to normal. I'm not sure what was wrong last night but maybe I did take out to muuch water.

if they're back to normal, it was probably the temperature. you should warm the water up to the same temp as existing water in the tank. heat up a few cups of water in the microwave if you're too impatient to let it sit for a day or two before pouring it in

Temp Shock Info
While some think it is extreme, the recommendation by Dr. Edward J. Noga, Professor of Aquatic Medicine, is to limit temp rises or drops to plus/minus 1F in 24 hours - that is optimum. In emergency situations, he recommends rising/dropping it only 1F per hour, I think for a max of 4F in 24 hour period. He suggests this has risks.

All it takes is a drop of 3 or 4F during a water change to bring on temp shock and ultimately a case of ich or velvet from chilling. If this happened, watch for flashing or rubbing against objects in the tank and white spots because they may be at risk for it.

The best way to understand it is to think about our body temp going from 98.6 down to 95.6 in a matter of minutes. Unlike us, fish don't self regulate their body temps. Rather, it is govererned by the environment. So when it drops or rises abruptly, their body temp attempts to drop or rise with it. According to Noga, tremendous energy is lost as this occurs and in that time, their resistance drops and it can last a day. Conversely, when an abrupt rise occurs, Noga goes on to say that low lying bacterial infections, such as columnaris can really take off.

pH Changes during Water Replacement
One other issue that could have been involved is a temporary pH swing. If you measure the pH of your tap water straight from the tap and then measure the pH of your tank, you may see a considerable difference. Mine comes out of the tap at 7.0 and rises to 8.0 if I put some in a bucket with an airstone overnight. This is because there are various gases compressed in the water. When water circulates in an open container - like a tank or bucket, the gases in the water equalize with the atmosphere. Gases like co2 will make the water more acidic, until it disipates.

Tanks also drop in pH due to aging over time. Mine is currently at 7.5, but was at 8.0 when I first set it up and later steadied at around 7.7. I fell back on water changes and it dropped to the current 7.5. There are things in my tap water that buffer the water so I like to do weekly water changes to keep the pH steady.

I'm thinking that if your tank is fairly new, you could have a high pH like I did and a low pH coming out of the faucet like mine does. If so, changing 30% of the water could have dropped the overall tank pH just enough to make them a little shocky.

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Recommendation
If your tank is small, consider handling your water changes the way I do. For a 10 gallon, consider keeping 4 gallons of water, with conditioner filled at all times. (2 for changes/2 for emergency changes). When you do a water change, refill it and put conditioner in it so it can sit a week and outgas and get to room temp. Keep the lid off and don't fill it to the top, rather allow it to have some space to the top so more water is in contact with the atmosphere. When I go to do a water change, I stick as many jugs as I need into the laundry tub in about 2 inches of hot tap water, for about 3 minutes. I use to measure it, but learned how long it took to get in the ballpark. With only 20%, you will not alter the tank temp much if you get the water in the bottles within 2-3F. The first few times you do it, give the bottle a good shake after 3 minutes(since hot water rises to the top of the bottle) and use the tank's thermometer to check it. Many thermometers can vary by several degrees so i use the tank's thermometer. In time, you'll know how long it needs to sit and won't need to measure any longer. This process of aging the water, allows the pH to get to where it wants after outgassing, and the temperature to at least get to room temp. You'll only need to bump it a few degrees and maybe not all, depending on your tank and room temp.

Hope this helps


Last edited by Cory_Di at 04-Feb-2005 17:28

Last edited by Cory_Di at 04-Feb-2005 17:30