Beneficial bacteria remove ammonia and nitrite- so your bacteria are fine.
They produce nitrate. What you are seeing is normal.
Several ways to reduce nitrate:
1) Less in. If you feed less fish food (especially high protein food) there will be less nitrogen entering the tank.
2) If you are currently using a plant fertilizer, do not add nitrogen. Add the other things. Plants may be able to use the nitrogen best if they have good levels of the other things.
3) Increase removals: Water changes. Larger, more frequent.
4) Encourage the plants to grow faster by seeing that they have the right light, CO2 and the other nutrients that are sort of lacking in fish food. Fish food usually has plenty of N, P and most trace nutrients. Usually lacking in potassium and iron.
API kits usually have a life of about 3-5 years, but some seem to last longer.
GH is the one I have found to not respond after about 5 years. The others seem to give the same results as other kits that I have (several sorts).
Agreed on the new test kits. If you gonna use them, you might as well get accurate results to work from.
In any case, 40ppm nitrate is nothing to worry over. Just a sign you have nutrients left over for some new plants to thrive from. Try adding some fast growing floaters like salvinia or frogbit.
Truthfully you are not neglecting you filters if they are still providing good water flow. Unless you bleach them, cut the power on them, or overclean the media in them, they will always have beneficial bacteria growing on them. Nitrate is the final product of a working biological filtration system.
The only way to eliminate nitrates naturally other than water changes is anaerobic bacteria living deep withing non-oxygenated soils (occurs naturally not to be concerned with at this time) or finally adding plants that will use the ammonia before the bacteria convert it into nitrate.
So chill, your doing fine you slacker...
Test kit too old??????
Hello fellow fish and plant enthusiasts.....having just got back to being SERIOUS about my precious aquariums, Ive got back into my weekly routine......30% weekly water changes, testing, keeping every speck of dust off of my aquariums,talking to my fish and plants, etc.....I have an API Freshwater Master test kit that Ive had for about 7 years......Im wondering if the reagents go "bad" because of age......In the last 3 weeks, since I started the process of getting my aquariums back in show form,Ive done my water testing....ammonia,0....nitrite,0....nitrate,10,ph ,7.2,thats in my 55 gal. with the 1 lone Anglefish, clown loach, and kuhli loach,...... the other 55 gal aquarium has a significant load of guppies, which most of are fry....a few adults, but not what I would consider a huge bio-load for a 55 gal aqaurium, with 2 outside filters running.....I just tested for nitrate, ammonia, and nitrite in the :guppy" aquarium..ph,7.6......ammonia,0.....nitrite,0....B UT, its showing 40 on the nitrate chart. Now, does this sound normal??? I realize that my filters were so badly neglected that there wasnt probably any "good" bacteria left in them, so should I just be patient,do the weekly water changes, and let the beneficial bacteria develope?? Or, could my test kit be innaccurate, since its not exactly. new....the fish(guppies) seem as happy as can be.....good color, very active, and not showing any signs of disease, stress, etc.....and they go crazy at feeding time....please give me your input, as I appreciate all of your sound knowledge......and thank you, all, for making this site a part of my life.......AGAIN!!!!!!!!!!!!!!!!!