Nitrate In My Tank Is Lower Than My Tapwater

[fry_lover]

When i did a water change yesterday on my 45-gallon 48-inch Community Set-Up, the Nitrate test kit indicated a reading of approx 5mg/l in fact its one of the lowest readings (closest to 0.0 Nitrate) i have ever had in a tank and i'm chuffed. Hadn't done a water change in 14 days before either. I also did the test TWICE and the tap-water test TWICE to confirm. Its well planted and thriving, so i guess thats helping with my nitrate, even though its pretty heavily stocked. I would guess about 50+ community fish averaging about 1-inch each, and fairly lavish feeding really. I also found one dead fish rotting away!!! Not worried though it was an LFS corydoras purchased about 5-6 weeks ago and everything seems fine. In fact the colours of my rosy tetra's and some my plaites is awesome!!! Every fish is very active.

Anyway, the reading from my tapwater was (and usually) is about 20-30mg/l so it just feels weird taking out water and putting water in thats HIGHER in nitrate!!! I kinda feel like i was doing my fish a dis-service!!!

When i tested my x2 cichlid tanks (67 gallons each) the Nitrate readings were approx 50-60mg/l

I know water changes are more about JUST reducing nitrate (growth hormone inhibitors for one) though....

If my nitrate readings are this low, should i consider altering my water-change routine, i normally advocate and do 30-35% per 7-10 days, shall i just do about 10-20% per 7-10 days?

I am a big fan of fairly aggressive water changes (up to 40%) every 7-10 days depending upon the set-up, but i feel bad about putting in water thats HIGHER in nitrate than whats coming out.......

 

[rdd1952]

Your test kit could be the problem. The ingredients in bottle 2 can lump (the reason you have to shake it for 30 seconds) causing faulty readings. But if you were testing both at the same time, that shouldn't be the problem (unless you tested the tank water, didn't believe the results, tested again and then tested the tap water giving the lumps an estra shaking to break up).

Of course live plants will consume some nitrates but shouldn't come close to consuming all of them. Are you running any type of nitrate removing media or sponges in the filter?

Since you did the test after the water change the results should have been close to the tap water since you put 20 to 30 ppm water back in. I would give it a week and test aain before your next water change and again afterwards and then do the math to see if the resulting level makes sense.

 

[fry_lover]

Your test kit could be the problem. The ingredients in bottle 2 can lump (the reason you have to shake it for 30 seconds) causing faulty readings. But if you were testing both at the same time, that shouldn't be the problem (unless you tested the tank water, didn't believe the results, tested again and then tested the tap water giving the lumps an estra shaking to break up).

Of course live plants will consume some nitrates but shouldn't come close to consuming all of them. Are you running any type of nitrate removing media or sponges in the filter?

Since you did the test after the water change the results should have been close to the tap water since you put 20 to 30 ppm water back in. I would give it a week and test aain before your next water change and again afterwards and then do the math to see if the resulting level makes sense.

thanks, i know all about the reliability (or lack of it) of Nitrate testing kits, i ALWAYS shake the nitrate kit bottle and actually smack them on a hard surface intermittently also as previously advised, but your points are valid and many peeps dont know about this

The test kit isnt really the issue though i dont think, as indicated i tested TWICE on tap water, tank water and also my cichlid tank

Not using any nitrate remover

 

[rdd1952]

Is the tank/tanks heavily planted? I can't think of anywhere else the nitrate could go. If the plants (or algae) didn't use it then I don't have a clue where it could have gone because as you know, the only ways to remove nitrates are by water changes, filter media/sponges (not certain how well those work as I''ve never used them) and consumption by plants/algae. If there's another way, it's news to me.

 

[fry_lover]

i refer to my first post

"Its well planted and thriving, so i guess thats helping with my nitrate"

 

[rdd1952]

Sorry, missed that....twice. That's what happens when you get old.

 

[fry_lover]

LOL

dont worry dude!

just reading your thread on fishless cycling