Urgent Help Needed!

[GTS_MAD]

i dont get this at the moment, if my levels was 8pmm and iv done a 90% already and the reading has moved really, i would of though it should of

am i doing something wrong?

also would a 100% change benifit me?? in stead of lots of 90% as i work very long shifts and its hard trying to find the time and really dont want to lose more fish

 

[OldMan47]

If my memory serves me, you can't measure much more than 8 ppm with a typical test kit. That means that a reading of 8 ppm is at least that high. A 90% change can be followed by another one the same size an hour later. You really don't need to wait the hour but I like to give my water time to mix properly before I test again. As far as deep cleaning the gravel, when I do a water change on a gravel substrate, I plunge the gravel vac all the way to the glass bottom. That way all the dirt trapped in the gravel gets removed. Then I move over a couple of inches and repeat. I do not like releasing my gravel mung into the water so I wait for the vac tube to clear before moving over.

 

[GTS_MAD]

SO would it be better to carry on with 90% changes or start again with 100%

 

[OldMan47]

I have no idea how to do a 100% water change without the fish becoming quite dry. What I call a 90% water change is when I drain down until the fish are having trouble swimming, because there is so little water left in the tank. Any more than that is bound to result in serious stress to the fish. My own guess is that the half inch or so above the substrate and the water trapped in the substrate are between 5 and 10% of the total tank volume in most cases. With nothing but guppies in the tank, I would let them swim in the small puddles you might have due to an uneven substrate if you got carried away draining, but many fish need more space than that, even for just a few minutes.