Nitrate spike= big PWC or not?

[HappyHooligan]

90g fowler, 4 fish. I don't use a sump, just Octopus skimmer and weekly 5% PWCs.

My nitrate went from it's consistent level of 5-10ppm to close to 40ppm.
I did have a green chromis disappear a week or so ago but no measurable Amm. or Nitrite recently. SG and PH values read consistent levels.

I noted the nitrate level, and did a PWC as I normally would. This lowered the level to about 20ppm and it appears to be staying at that level.
Should I do a larger PWC or continue with my usual PWC routine?
I'm confident the fish will be okay but am a little worried about my inverts.

 

[dannyb]

It be best if it was 0, Or as close as it could be. But 20ppm is ok. Any higher then you should stress abit. I cannot get my nitrate levels below 20ppm, I've tried everything. But fish are fine and happy.

I'd be doing more like a 20% water change weekly, imo 5% doing nothing really.

 

[CaptainAhab]

20's not a big deal for FOWLR. However, mathematically you can not be at 40ppm, do a 5% water change and get to 20. Simply can't happen. Either your test kit is bad or the operator is

 

[HappyHooligan]

I tend to go worst case scenario, so I would guess somewhere in that area
Sometimes I kind of struggle with those API color cards.

 

[HappyHooligan]

I'd be doing more like a 20% water change weekly, imo 5% doing nothing really.

I guess I've considered my bioload to be pretty light, my parameters were always stable so I stayed with the 5% PWC. Probably time to to bump that up.

Any suggestions on vessels for mixing 15-20g of water?

 

[CaptainAhab]

20g brute trash can. Holds 15g easy, $15 at HD