PWC? How much how many times.

[martiniduck]

I have been doing 50% PWC every week. I have my tank at its capacity for fish, and I think I tend to over feed them. Two tanks both community, one 10G and one 29G. The 29 G has been running for a year and the ten gallon for six months. When doing test on the water, I don't get any Amonia readings, no Nitrate, but my Nitrates are a little on the high side. I have a hard time telling the difference on my test card. They are somewhere between 25-100, the shades of red in the test tube and on the card are hard to see a difference in shade. Back to the issue. I have read in some books that the more changes and the bigger the PWC the better and some books that say that too big of a water change will shock a fish. I have not have any health concerns with my tanks, in fact my mollies, guppies, and platies all have bread monthly. How often is a PWC to be done and how much should be changed?

 

[dkpate]

When mine get that high, I change the water, cause I can't tell the difference between the colors that high up either. If I have to do it twice a week, I do it twice a week. To help with the problem, I rinsed my filter media in old tank water, and did a good cleaning with the vacuum on the plants and decor.
Good luck!

 

[mfdrookie516]

i do 50% weekly in all my tanks. if nitrates are high, you need to be figuring out whats causing them... dirty filters, overfeeding, gunk built up, things like that... otherwise, id say keep doing 50% pwc's

 

[Blueiz]

Agree with mfdrookie.

A note on the amt of water changes. If you are adding crushed coral, or something of the like to your tank to keep the ph up, peat to lower the ph, or really anything that takes time to alter the water chemistry, you will not want to do large water changes on your tank because the new water will be a lot different than the existing water. However, if you are not altering the water by means that take time to take effect you can change as much as you like however often you like.

What kind of test kit are you using? You may want to test your source water for trates, there is a possibility that the reason your water changes aren't helping get them down is because they are in the source water.

 

[sumpnfishy]

Of note: I've done 20% water changes as needed. My nitrates run on the high side but have not had any fish related issues. I finally figured out my well water has nitrates in it (as Blueiz mentions). The only issue I normally see is some algae growth (loves nitrates).