Wow. That's a lot. Even when I have to make an adjustment its literally 2.5 ml.
Do you have a digital pH meter? I would use a different test kit or digital meter and test again. Something is off. If you confirm it with additional testing methods then I would day do a water change.
Hi neaderw, I strongly suggest that you dump the nutrient solution and start over. You may find the following helpful:
How to Mix TG Nutrients