No Nitrates

Question
QUESTION: Well I really havent had a problem per say but i currently have a 150 gallon aquarium with 2 oscars, a fire eel, placo, pictus catfisha and a electric blue crayfish, and i have had this tank set up for about 8-9 months now and i had a huge problem with the ammonia about 2-3 months a got it was reading about 10 ppm and i know that is WAY TO HIGH but then after the ammonia droped i havent had a problem with that at all.  I currently have a Rena XP3 which i have had since i bought the tank and i recently added a Rena XP4 right before the HUGE ammonia spike.  I currently keep my water at 80F and the ph about 7-7.2 and i usally keep a really good eye on my nitrogen cycle so that the ammonia spike doesnt happen. I tend to do about 40 gallon water changes every 8-10 days and for some reason after my huge ammonia spike i test my ammonia and its 0 allong with my nitrites and the thing thats weird to me is that i test my nitrates and they show up as 0 and i have done a lot of reading on taking care of fish and all that good stuff and they usually say that the nitrates shouldnt go past persay 20-30 ppm and i test none i was woundering if that ment that i had a very well established biofiltration or if something else was going on in my tank well thank you for your time and hope to hear from you soon
    Sincerly Robert Mackey

ANSWER: Hi Robert:  It sounds like to me that your tank has balanced itself perfectly.  Probably a bunch of little things are working together to keep your chemicals perfect... between the bio filter, and the tank bacteria... things seem good... I wouldn't change anything but I would continue to keep an eye on my chemical levels.... Good job!!!!   dave

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QUESTION: Well thank you for the good news Dave thats what i thought it might be.  On the other hand i have asked several places where i live and a couple of them said that was weird and it souldnt bee like that but ever thing is ok and thats all imm worried about but last night i had to do a regular water change a normal 40 gallon and it was time for me to check my canister filters i recharged the 3 Rena Nitra Zorbs and added a new Rena Bio Chem Zorb and i have never tried this one but a Rena Super Activated Carbon, i tend to use 3 Nitra Zorb and 2 bio, chem zorb, and i have about 30 pieces of the bio stars and about 3 boxes of the ceramic rings, and i tested my what this smorning and my nitrates had rose to about 7 ppm and i was kinda bummed about that i wasnt sure if because i cleaned my canister filters (did not touch my biological) that maybe i messed up the factor that was helping remove the Nitrate???

Answer
Hi Robert:  A lot of places (including where I work) the employees don't always understand water chemistry or the factors that go into making great water work in a tank.  They understand the bio filter and its function but do not really apply it to chemistry in water.  The fact that your nitrates are high but your ammonia is low is actually great news... that says to me that your filter has already changed the ammonia to nitrate and I bet by tomorrow your chem levels will be normal.  The nitrogen cycle starts with fish/fish waste/extra food, becomes ammonia, then nitrate/nitrite, and then becomes beneficial as it continues along the nitrogen cycle... live plants use nitrogen to grow, etc.  But inside of water are many little factors that change things on a chemical level... like water temperature...for example.. hotter water doesn't hold oxygen very well which is why in the summer ponds grow algae... because algae gives off pure oxygen and eats the stuff in a pond that accumulates when water is low on oxygen... it is all a cycle of balance that the forces of nature use to create a living environment... the forces of nature include bacteria, chemical/chemical reactions, etc.  You have managed to find a perfect balance there in your tank... keep me posted.... dave