I find that you found that much Potassium interesting. As all my tanks are heavy bio-load ( lots of cichlids!) and feeding daily, I imagine mine would be the same.
Im curious about what types of fish you have? I dont think Ive ever seen a post on your fish.
Yeah, I also wonder, what is the fish population in this tank? Just kind of easier to understand the amount of food by fish population - I've never ever weighted the fish food while feeding... And how many plants in the tank relative to fish?
Also, do you add any fertilizers at all in this tank?
I'm still skeptical, myself, about that much K coming from fish food. I just can't account for it any other way and, as I said, I calibrated the new test kit and also repeated, several times, the test on my tank water. If anyone can challenge this, I’d love to hear about it.
I add urea (2 ppm NO3 equivalent daily), .1 ppm PO4 daily, ever-shrinking traces (except Fe, which was increased) and a little Mg when it drifts lower than ~2 ppm. Interestingly, Ca holds steady at ~8 ppm, which also indicates a fish food contribution in balance with uptake. Gravel is inert, so no GH or KH contribution there. KH is well below 1 ppm.
My current 38-fish load (from AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor
1 x Corydoras C079 (Corydoras loxozonus)
1 x Featherfin Catfish (Synodontis euptera)
1 x Oto (Otocinclus vittatus)
1 x Bristlenose Pleco (Ancistrus sp.)
1 x Kissing Gourami (Helostoma temminckii)
1 x Honey Gourami (Trichogaster chuna)
1 x Molly (Poecilia sphenops)
3 x Harlequin Rasbora (Trigonostigma heteromorpha)
3 x White Cloud Mountain Minnow (Tanichthys albonubes)
10 x Cardinal Tetra (Paracheirodon axelrodi)
4 x Neon Tetra (Paracheirodon innesi)
1 x Zebra Danio (Danio rerio)
1 x Longfin Zebra Danio (Danio rerio)
1 x Blue Gourami (Trichogaster trichopterus)
3 x Guppy (Poecilia reticulata)
3 x Glowlight Tetra (Hemigrammus erythrozonus)
1 x Swordtail [Male] (Xiphophorus hellerii)
1 x Siamese Algae Eater (Crossocheilus siamensis)
This is way off the scale, so I wouldn't encourage anyone to match this quantity. Those fish that can outgrow the tank (29 gal), already have. According to AqAdvisor, I'm well over 200% capacity. Also, I don't have any bio-media in my filter, so that would make them even angrier.
Lots of plants, mainly stems, so good cleaning and hiding capability.
Just don’t take the test results too seriously. You may be making the wrong interpretation simply because the test kit cannot read low concentrations correctly.
As you can see, I calibrated both kits and they both differentiate well between 5 ppm and 10 ppm.