Multiple Tanks, Ro Water, High Ammonia?

Right now I've got 2 10 gallon tanks and 1 30 gallon tank.
One of the 10 gallons only has a small pleco and a female betta in it.
The 30 gallon has a couple goldfish.
The other 10 gallon is empty (been trying to figure out water problem described below before putting anything in it)

Spent months struggling with the tanks on our crappy (hard) tap water that uses chloramine and has a ph of over 8, so I could never get the ammonia to safe levels. Decided to buy an RO unit.
Didn't seem to help ammonia "problem"?

Run the full gamut of tests against the water straight out of the RO unit, measures 0 in everything and ph of 7 (even with the API tests).

Put all brand new (washed) rocks/decorations in the second 10 gallon, all new filter/media, etc and filled up the tank (no fish added). Tested that tank the next day, ammonia over 8ppm via the same API kit that said 0 before and nothing else added that should give false positive like Prime or any declorinators, but did add Replenish. Nitrite/Nitrate is still 0ppm.

Next step was to put in Prime (know that can cause false positive) and beneficial bacteria, wait a couple days and test again. No change, still 8ppm+ (Nitrate/Nitrite still 0)
Bought a Seachem ammonia tester (that tests both kinds of ammonia) results said 0 ammonia. Bought a little Seachem "hang it in the tank" ammonia tester... 0 ammonia.

Other 2 tanks, identical results, so this is getting very frustrating. Tried doing multiple days of 50-75% RO/Replenish water changes in the tanks, reading of 8+ppm ammonia doesn't change. (Nitrate/Nitrite still 0 in all tanks)

Using the API kit, every time I test the RO water, 0ppm. Every time I test a tank (fish, no fish, water change, brand new tank, etc) 8+ppm ammonia. (Nitrate/Nitrite still 0 in all cases)

Does anyone have any idea what might be going on? Are the API tests really that messed up? Or can something else be giving false ammonia readings with the API kit that we're not considering?

The fish all seem to be acting normal and not showing issues with the water, but I'm worried there is something going on that we're overlooking so looking for some advice.

 

In recent months there have been reports of the API ammonia test appearing to be way too sensitive to ammonia. It gives dark green, 8 ppm readings in tanks where fish seem to be fine.

The API test isn't any worse than any other aquarium test kit. I think they just have a bad batch.

The Seachem Ammonia Alert only works when pH is >7.

Most ammonia is going to be from fish and decomposing waste matter. Tap water isn't going to contribute much, just a fraction of a ppm every water change, unless you did large water changes daily.

 

If it's the API kit, we've had a lot of bad luck. We started with an older (but not expired) kit. Thinking that was bad, we bought a brand new one. Same results.

We aren't using normal tap water anyway, we're using RO water/Replenish and I wasn't expecting a brand new tank with no fish in it to have ammonia levels of 8+ppm, which is why we didn't know what was going on.

Good to know the Ammonia Alert thing will only work on ph >7, so that may not be working since our PH is only 7 via the RO unit, but the full Seachem dual ammonia kit should work with a PH of 7?

 

I don't think the Seachem ammonia test has the pH 7 warning so it must somehow still work. The Seachem total ammonia test just raises the pH to like 10 so all ammonia becomes ammonium so that will obviously still work.

I used RO for the first 12 years or so of keeping fish. During that time I tried the Seachem ammonia guard and ammonia test and they gave me results that didn't make sense or were difficult to read.

Seachem Replenish doesn't replace kH which you'll need to keep your biofilter going and pH stable.

 

Thanks for the tips on the Replenish not having kH.

Anyone have any ideas why we're getting such high ammonia reading from the API kit when it works fine before it's in the tanks?

 

As far as I can tell, the yellow comes from un-reacted reagent from bottle #1. Reagent that reacts with ammonia turns blue so the more green the resulting solution is, the more ammonia there is. However, if they don't put enough reagent #1 then there isn't enough yellow and a low amount of ammonia will turn it all dark green. Ammonia that's zero or very near zero will be OK though.