Why Didn't My Water Change Work??

HI guys!
I did a 50% water change on my 10 gallon divided Betta tank; it's the first "big" one I've done on it since it has been divided {3/11/18 was when I divided it}.
I checked the params like I always do before a water change and they read: .25 ammonia, 0 nitrite, 5 nitrate.
I did my water change as usual with conditioned water, waited an hour and then tested it only to find that they are the exact same params as before I changed it.
I waited two more hours to check it thinking I needed to let it settle a bit more...and still the same.
Can someone tell me why this is??!!
I plan on doing another 50% water change tomorrow evening as well. I'm starting to do them daily to battle the fin rot one of the Bettas is experiencing.

 

What kind of a filter are you using and are you vacuuming out the gravel as well?

Also, check your tap for ammonia and nitrate

 

Have you tested your tap water for ammonia and nitrates? Some water has both.

If you do find both in your tap water use Prime. It can detoxify both.

 

What kind of a filter are you using and are you vacuuming out the gravel as well?

Also, check your tap for ammonia and nitrate

I vacuum gravel weekly on Saturdays

I have the Aqua tech 5-15 filter {it came with the tank; 3 years ago)

I do need to check the tap water, I know it's extremely hard {8.2}
I guess what puzzles me is every time I've done one in the past 2 hours after when I check it is always 000 really frustrating ‍♀️

 

Have you tested your tap water for ammonia and nitrates? Some water has both.

If you do find both in your tap water use Prime. It can detoxify both.

Yes, I need to test my tap water! And I use prime for every water change as well as let the water sit from 12-24 hours before adding. Thanks for your comment!

 

I have really hard tap water, but it doesn't have ammonia or nitrates in it. Go ahead and test the tap water real quick and see if that is the issue...if it isn't then your going to have to clean your filter more than likely.

 

I thought I was going nuts a few years ago when I kept doing water changes and the nitrates stayed high, then got even higher. Checked my tap water and it had a horrific nitrate spike. I've used Amquel Plus ever since.

 

What kind of tests are you using?

The difference between 0.25 ppm and 0 ppm ammonia with API drop tests is quite subtle (at least for my eyes) and unless you've seen both before you might mistakenly consider 0 for 0.25 (at least I had this exact issue).
5 ppm for nitrates also seems to be the lowest non-zero level that can be shown by API test - I think it might still show the same even if you have half of it.

Edited: I uploaded a picture to show what I mean. I took some water from one of my tanks - I believe it has ~10ppm of nitrates. Then I diluted it in half, put some into the second vial, then again in half and put it in the third vial etc.
If we assume I had 10ppm in the beginning, the last vial should have 1.25ppm

The problem is that I don't see much of difference between 5ppm and 2.5ppm and between 2.5ppm and 1.25ppm. Well, there is a difference when you hold it side-by-side, but if I randomly choose any of these vials, I'll have some hard time saying for sure which one it was just using the color chart.

 

So I finally found the time to test my tap water... yall I had a fit...


Thank you all for the responses! I think my problem was that I didn't add enough conditioner/didn't let the water sit long enough