Water Chemistry Guru's

[yargo]

I have a water chemistry problem that is baffling me. My nitrates are high @ 20ppm. All the other water parameters seem to be OK. The tank has been running for 11 months. I’m using fluidized Bio-Pellets; they were introduced to the system about a month ago @ the minimum recommended dosage. Water changes are every 2 weeks at 15% minimum. All tank inhabitants are accounted for so the death of something isn’t causing the spike. Does anybody have any suggestions on what would be causing the spike & how to correct it?

NH3/4 (ammonia) 0.0 ppm
NO3 (nitrate) 20 ppm
NO2 (nitrite) 0.02 ppm
PO4 (phosphate) 0.01ppm
PH 8.0
DKH 7 (a little on the low side)
Ca 400 ppm
Mg 1300 ppm

[hound96]

are you using tap water or ro water?

[hound96]

also how much do you feed every day

[abcha0s]

Are you adding a bacterial supplement? - Microbacter 7 / Zeobak

It sounds like a bacterial imbalance of some sort.

[sphelps]

Most likely it's just a simple build up of nitrate that accumulated over the 11 months as a result of over feeding and or lack of nutrient export. Could you post your tank and sump size plus the skimmer you use?

Once a build up of nitrates is present it can be difficult to bring down, 15% water changes biweekly alone will have little effect. First fix the source which could be an over stocked tank, over feeding, or poor skimming. Then do larger water changes less often, for example 30% monthly is more effective than 15% biweekly. However you should consider larger changes in the 50% range if possible to make a larger difference. Even doing this will take some time.

[yargo]

100% RO/DI water with TDS 137 ppm in & 0 ppm out. I feed pellets when the first hits the sand bed that's it, so I don't think it's over feeding.

[paddyob]

How much or how often do you feed? And what?

This is, believe it or not, generally related to mysterious levels of NO3/PO4. More food = more waste (both food and poo).


Most people believe they do not overfeed, and that there has to be some crazy thing happening to the tank.

Try reducing your feeding by say, 25%. Watch your levels and see if there is any change. 25% reduction in food won't hurt your fish and its a no risk trial.


I don't think RO has anything to do with it. I don't run RO (NEVER have) and I never have any NO3, NO2, PO4. Go Tapwater, tapwater, tapwater woooo! (use any rhythm while singing