Epic Nitrate Spike!

[Jnoosh]

Hey all,
Last week my tank was doing fine, next to no nitrates at all.
Two days ago I cleaned my filter as water flow through it (wet/dry trickle filter) was having some issues.
I did a test today and its off the scale! I have a tetra nitrate kit, it goes from clean (no nitrates) yellowish ( low) orange middle and light red (high) mine is REALLY dark red, so above what my kit can read (100) I retested and it was the same! So quickly did 50% water change witch brought it down some what.

I rinsed the top level of the filter media (spongey stuff) with old tank water, and then put it back in. Didnt touch the ceramic noodles or anything.
Did my filter rinse cause the spike? or something else? If so how should I be cleaning the filter? and have I caused my tank to start the cycle again? Its only about 3 months old and I am a newbie, so any help would be greatly appreciated.
Thanks,

Josh

 

[ZoddyZod]

have you tested the nitrate readings from your tap water?

what is the size of the tank?

what is the current stocking of the tank?

how often do you perform water changes?

 

[Jnoosh]

Tap water = pretty much 0
Tank = 25g/100L
Stock = 2 x junior firemouth (2.5 & 3inch), 2 x Corys, 1 x plec, 4 x scissortails (2inch)
Water change = 8 buckets, approx 30% every weekend along with a gravel vac.

thanks.

 

[ZoddyZod]

hmmmm, you aren't massively stocked so it doesn't look like your tank is naturally producing such high nitrates in the week between water changes.

I'm not familiar with the kit you are using, is it a 2 step/bottle process for testing the nitrate? Maybe you made an error when mixing the test soloutions?

 

[Jnoosh]

hi,
You put 14 drips of 1 in, 7 drips of 2, a spoonful of powder and then 7 drips of three. I did it twice to check for errors on my behalf?

 

[ZoddyZod]

hi,
You put 14 drips of 1 in, 7 drips of 2, a spoonful of powder and then 7 drips of three. I did it twice to check for errors on my behalf?

blimey that sounds quite complicated! The 'spoonful of powder' seems to be the most likely place to causes false readings (not a very accurate measure) but I am not at all familiar with this type of kit.

 

[Rynofasho]

That kit does sound like you're making potion haha.

A dirty substrate will give you high nitrates too. I would not expect a nitrate spike from cleaning the filter though, no. If anything I'd expect a decrease.

Vacuum your gravel a few times (deep clean it), and get an API liquid test kit for nitrates instead of crafting that potion of yours!