Every Water change......

[kheta111]

Hey guys,


I have 40 gallon (tall) planted community tank. Almost every time I do a 25% water change (which is usually weekly/bi-weekly) I lose fish. They usually change colour act sick and die over night. The strangest is part is that if I focus say on my Apistogramma caucotoides, I'll always lose the male and one or two females while one are two females are totally fine. Or again I have a gang on 10 tetras I'll change the water and one or two will die while the rest are completely fine. I thought it was maybe my tap water, but I use an appropriate amount of prime. I that it was the hardness of tap water so I switched to RO water... same results. All the water stats seem normal, I don't get it. Could it be filter changes? I have a penguin bio-wheel filter. I rinse the new filters out before switching them in. It seems strange to me.. How can one or a couple individuals of the same species be mortally effected while their tank mates be completely fine?

 

[sunscream13]

I have the same type of tank and that does sound strange. Could it be your supplier??

 

[sunscream13]

Your ammonia at 0? Nitrites 0?

 

[Autumnsky]

Does your water company use chloramines in the tap water, not all water dechlorinators can break /bind them? Some require additional up to a double dosage, like Prime.

Are you using correct temp water added back in?

Do you rinse the filter pads in tap water/not treated water? Replace the pads?

 

[UntimelyLord]

What are your ammonia, nitrite, and nitrate measurements? Is the pH of your tank the same as the pH of the new water?

Could it be filter changes? I have a penguin bio-wheel filter. I rinse the new filters out before switching them in.

So you change out the filter cartridge with a completely new one? This could be your culprit. Beneficial bacteria live in your filter and you don't want to completely get rid of them; I don't change filter media unless it is falling apart, and even then I'll run the new media with the old media for a couple weeks.

 

[Autumnsky]

One of the most valuable things I learned a few years back now, was as mentioned, never rinse the filter media in tap water that has not been treated with water conditioner, or rinsed out in old pwc tank water. And do not throw away your BB colony in your filter pads. Use them until they fall apart.

Removing the filter removes your larger colony of beneficial bacteria, the wheel has some, but not really enough to process a fully stocked tank, or a liberally fed tank.

Check out the Aquarium Advice article Getting Started in my signature for a bunch of useful information.

 

[sunscream13]

Most pumps use a separate bio media so you can change your filter every month. I change my filter at least once a month with no problems.

 

[BBradbury]

kh...

Tank problems are water related. You have to keep a balanced water chemistry. The best way to do this is by removing and replacing most of the tank water weekly. This means not missing a water change. Small water changes no matter how often you do them, still leave most of the old toxic water in the tank. By changing a lot of water and doing it routinely, you'll guarantee a steady water environment for whatever you have living in the tank.

Avoid putting chemicals into the water other than the standard additive to remove chlorine and chloramine. RO water is sterile, no mineral content to help balance the water chemistry. To me, it has no place in the water keeping hobby.

Remember, change most of the water weekly, no slacking. Keep things simple and there's little chance you'll forget to do something that will negatively affect your tank.

B

 

[Andy Sager]

Usually, deaths after a water change are related to the change in the water chemistry in the tank being too much for the fish to handle. Since you are not losing all the fish, the new water itself is probably not the problem. Since you are losing fish right after the water changes, it sounds like a reaction to the change. I would suggest smaller amounts of change more frequently than the larger changes you are doing to see if this stops your issue. If it doesn't, you may want to look into the health of your fish stock as a whole. You would be having some weaker fish in your stock that cannot handle the changes in chemistry. (That is assuming the water chemistry is within reason to begin with.) That would speak to the diet you are feeding and circumstances the fish are living under. You may need to address these issues to stop the loses.

Hope this helps.