I topped off the tank with distilled water, then ran a few tests.

Temp 78

specific gravity, Red Sea hydrometer  1.017; Deep Six Hydrometer 1.020 (adjusted, unadjusted it’s close to the other reading). Perhaps I should have topped off the tank with salt water.

Ph (Red Sea test kit) came out some color that didn’t match the chart. In the past that means the Ph is low.

I scooped out about 20 oz of water with a large tumbler, replaced it with salt water and retested. 

The Ph was an even paler blue. The specific gravity was unchanged with the Red Sea hydrometer, but went up a scant amount to 1.021 (adjusted). I added 1/4 tsp superbuffer in 1-2 oz distilled water. (sigh) I really messed up the water chemistry tremendously when I did that first water change last week and I haven’t been able to get all the numbers right since then, even with successive water changes.  At least the hydrometers are giving consistent readings, unlike before when both were giving readings all the way up and down the scale on back-to-back testing. I’ve got to get the specific gravity back up—and get consistent readings from the hydrometers so that I know what the specific gravity is.