water issues

Question
QUESTION: hi david. i tested the water in my goldfish tank today and everything was great except for VERY high nitrites. this worries me quite a bit and im not too sure how to lower the level of the nitrites... and also overnight the ph levels in my 55 gallon tropical tank went through the roof, and i dont know why. my fish are super stressed and two of my tiger barbs have died. what causes this??


ANSWER: Hi Kyle:  Do a 25% water change on the goldfish tank and then retest the water after about 4 hours.  Make sure to clean the gravel while cleaning the tank.  Let me know what the new levels are.

Have you added anything new to the tank??? like coral gravel or a new rock?  When you say your pH is through the roof... what does that mean in terms of chemical value?  Fish to not react well to drastic changes in chemical or pH... Tanks do not spike pH without something being taken away or added... can you help me identify which may be the case?   dave

---------- FOLLOW-UP ----------

QUESTION: i did the 25% water change and added a bit of aquarium salt and its a normal level now. as for the tropical tank, the only thing i've added lately was a log decoration from petsmart. besides that, i added 3 tiger tiger barbs and a red tailed shark about 2 and a half weeks ago. could that have been too many fish at once?? the tank had already cycled for 3 weeks before i put them in...

Answer
Hi Kyle: When we have issues of a pH increase normally three things come to mind... Limestone rocks, coral gravel or a change in well water.  Two or the earth metals, magnesium and calcium are known to raise pH in water and in rarer cases too much oxygen can raise pH as well.  What is your pH level?  most fish can tolerate 6.5-8.0 in pH but not all fish can.  The danger with fish and pH is the sudden change over two points on the pH scale such as a drop from 8.0-6.0.  Fish have an internal organ that helps them adjust to different pH conditions because in the wild throughout the seasons and year their environment change.  I have had a few readers who have freaked out over a change of only .2 so it is important to know what your pH was as well as what it is now.  dave