Is it good for the fish to do full water changes?

[juanrivas16]

I just want to know if doing complete water changes will harm the fish

 

[Bubble_B0y]

It depends.

If the pH, temperature etc... is exactly the same, then it's safe.

Also, as long as there is sufficient good bacteria in the filter, and it's not harmed when doing water changes, then it's safe.

Having said that, I wouldn't do a 100% water change.
I would do several 50% water changes over the course of a week.

 

[Samzter]

Hey! It all depends on the stock and tank. But I really advise against it. It may kill all the beneficial bacteria and shock the fish. So I really wouldn't do it.

 

[Aquatic_Adam]

+1 to the listed reasons.

You're really better off (for the fish and for you!) just doing a series of 20-25% water changes over a few days if you really need to do such a large water change.

Good luck!

 

[aaronjohn20]

Fish can actually be harmed by slow building nitrates, and then all-of-the-sudden, real clean water. Sorry, I hope that made sense. I've been up a lot lately lol

 

[jlk]

+1 to the above responses

It really depends on alot of factors. I do 100% & 75% water changes weekly but I also know the ph is exactly the same and the temperature is matched to 0.1 degree. Never lost a fish or a cycle. If something changed with my tap such as the ph, I would not be able to do this safely. Bare in mind, I keep extremely messy fish that are well fed and this is easiest way to keep the tanks stable for my particular situation. Wont work for everyone and many fish would be excessively stressed by being caught & moved on a regular basis.

 

[librarygirl]

I guess the first question is why you feel you need to do full water change? A series of back-to-back 50% changes would be better, assuming the tank needs it (e.g. if ammonia and/or nitrite are at high levels). Also with fish in the tank you'd need to keep at least some water in the tank for the fish, so a full water change wouldn't really be doable

With that said, I've accidentally done 75% water changes on my tank (left the automatic water changer running and forgot to check it lol) and the PH out of my tap is very different from my tank's PH and I didn't have any problems. But some fish are more sensitive than others too.

 

[juanrivas16]

Thanks for the advice,i am going to do 50% water changes