How is this possible?

[Cactuspixie]

Yesterday the nitrate reading in my 6ft tank was 5.0 but after doing a 15% w/c today, the level has increased! It's not the tap water- I've tested that. When I topped up the tank I used seachem safe, stress guard, and a couple of teaspoons of aquarium salt. I can't tell you what the exact reading is now, because using the api test I can't tell the difference between the 10.0 indicator and the 20.0.

 

[TheCommunityCichlid]

Your fish could have produced more. Or you took samples from different depths

 

[Cactuspixie]

I took both samples from near the top, and there was only 14 hours between samples. Could it have been the disturbance of the substrate when I used the gravel cleaner to siphon the water out?

 

[reefdiver]

If you don't vacuum regularly that will have an effect on your readings.

 

[Cactuspixie]

I don't know if I clean the gravel often enough or too often- I use the gravel cleaner to do a w/c every 4-5 days. I used to use a battery operated vacuum in between w/c but I have gone through 4 of them (2 of them were the expensive to buy but cheaply manufactured Eheim). I no longer have the foot long Pleco in that tank so it doesn't get very messy now anyway. There is a lot of wood and plants in the tank- I've tried to use mostly plants that are attached to wood so that I can move them to better clean the substrate. It's a fine balance though, between adequate cleaning and stressing the fish, isn't it? There is a large driftwood cave that I don't move, as the feather fins and upside down cats hide in there.

 

[Cynic]

A 15% water change would hardly change your nitrAte level at all so it's not surprising it would increase. But yes disturbing the substrate can release nitrAtes into the tank.

 

[Cactuspixie]

A 15% water change would hardly change your nitrAte level at all so it's not surprising it would increase. But yes disturbing the substrate can release nitrAtes into the tank.

Ok, I will have to try and find an easier method to siphon the water (easier than siphoning into buckets and emptying them) so that I can do larger water changes

Edited to add: I had thought increasing the frequency of water changes would compensate for the volume of them.

 

[Dreadz]

I ripped the 3 foot of hose off my gravel vac and stuck on a big length of garden hose so I could just run it straight out of the doors into the drain on my patio.

 

[Cactuspixie]

I ripped the 3 foot of hose off my gravel vac and stuck on a big length of garden hose so I could just run it straight out of the doors into the drain on my patio.

I'll see if I can do something similar.