3 Water Changes, 3 Nirtrate Tests...No change

[MAreefer1]

In the last hour I just did a 45% water change because my Nirtrates were at 40!Not my fault...it was my old test kit(I already posted a thread regarding that matter)...but the question im getting at is why are my nitrates still at 40? I just got a new test kit...changed 3 gallons...no change in nitrates, then decided to change another 3...still no change in the dang nitrates...and finnaly just finished doing the third water change of three gallons(total of 9 gallons for those who can do math, lol just kidding)...so why havnt my nitrates gone down?...Its a 20 gallon high reef tank...I have two damsels(less than 1 in. ea), and 5 turbo snails, and 1 peperment shrimp...does anyone know what is happening?

please help

THANK YOU!

...MAreefer1...

 

[LOTUS50GOD]

If you changed 3 gallon from your 20... and your nitrates were 40

you only changed 15% and that would reduce your nitrates to 34

another 3 gallons (15%) should have brought your nitrates down to 28.9

and another 3 gallon (15%) change should have brought your 24.6...

Most test kits I have seen do not distinguish between 20 and 40 well.... but be assured that your nitrate level is 24.6 with your given data....

In comparison.. if you would have done a 9 gallon water change... or a 45% water change..... then you would have reduce your nitrates to 22...

so the change is minimal

 

[MAreefer1]

so should I do a full 9 gallon water change tomoro?

 

[LOTUS50GOD]

If you do a full 9 gallons tomorrow....(one time) you will reduce your nitrates from 24.6 to 13.6; if you didnt create additional nitrates over night...

Are you gravel vac'ing too??? To make nitrates go down you need to get the detritus out of the sandbed.. If you dont its like painting a rusty car without doing the body work...