All right, here are today's results:
Recap: Tank was started Aug 30.
88 gallon tank with Safe-T-Sorb (1 bag, 40 lbs) as substrate.
Large flat rocks (neutral with respect to GH, KH, pH or TDS changes) have been installed across the back of the tank. This has taken up some of the water volume. I will take a wild guess and say maybe 5 gallons? Maybe a bit more. I am going to use 8 gallons, just to make the math easier.
Initial fill was done this way:
STS dumped in dry.
Tank filled to about 6" with lots of stirring, then siphoned out.
Refilled the same, and again siphoned out. At that point I moved the substrate around and put some old pond tablets under it. The 'tablets' were falling apart and more more like sand-sized particles.
3rd fill was to the top of the tank.
Tap water, dechlor.
I started adding ammonia, testing and adding until I had 5 ppm. Perhaps a bit more.
I also dosed macros (KNO3, KH2PO4, K2SO4)
Plants include 1 Anubias, some Valisneria, Hornwort, Water Lettuce, Duckweed and Azolla.
Filters are 2 Fluval 404 canisters. with sponges, floss and bio media. They were used, but dry, I assume all the bacteria was dead. I thought there were no chemical media in there, but today I cleaned them and found 1 nylon stocking with some coral sand, perhaps 1/2 cup, and 2 stockings of peat moss, perhaps 1-1/2 cup total.
Next day I tested the KH. Way high. I assumed it was the pond tablets. Ammonia showing, and a trace of nitrite and nitrate. I assumed these last 2 were from the fertilizer, not nitrifying bacteria.
Over the following week I kept track of the ammonia, nitrite and nitrate to monitor the growth of the nitrifying bacteria.
At the end of the week (yesterday) I tested the KH. It had dropped almost to 0. pH was also very low (test goes down to 6.2) I have seen this before with Soil Master Select. I added 2 tablespoons of baking soda. (Per math in post above, that should raise the KH by 4 German degrees of hardness). It was late last night when I added it, so did not wait for it to circulate to re-test. I also tested the NO2. It was off the chart. This has been developing over time, suggesting to me the bacteria are getting going, rather than the sudden release from the fertilizer tablets. (The pond ferts don't have NO2, anyway)
KH test was the API test, but I used 10 ml of water. At 7 drops (3.5 degrees) the water was no longer blue, but I would not call it yellow. At 8 drops (4 degrees) the water really was yellow.
pH was 6.6 according to 2 different tests.
TDS 538 (I have been dosing EI macros and micros, the baking soda last night, and ammonia, and remember those tablets!)
KH was tested using the 10 ml method. At 5 drops it was that 'not really blue, not yet yellow' and another drop made it really yellow. So 3 degrees (Side note: this is lower than average for my tap water).
pH over 8 by all the tests I have, probably 8.4 (Side note: this is higher than usual, but I have seen it this high before. Water company adds sodium hydroxide to the water)
TDS 221 (About average)
Chlorine and ammonia in the tap water show just about 1 ppm, exactly what it almost always shows. Chloramine in the water.
Drained the tank down until the water was lower than the top of the substrate, but perhaps still an inch or so in there.
Re-arranged the rocks. Added some more rocks (so I really will pretend the rocks and substrate take up 8 gallons of volume.) This caused a very small amount of clouding that settled very quickly.
Cleaned the filters. They had some silty stuff, from the substrate. I have sponges over the intake and they had some plant roots and dead Duckweed on them. I was not too aggressive cleaning them, more sloshing the media in the used tank water, not really squeezing them much at all.
Refilled. Hose was aimed over the rocks so it did not stir the substrate much at all, and the fill was almost perfectly clear. Not quite, but an hour of running the filters and it was clear.
The plants did not like the ammonia. Anubias was in very bad shape, but new growth showing. The Vals were soft at the last few inches of the leaves, but the crown, root and several inches of the leaves were fine. I am sure these will recover. Water Lettuce not affected. Duckweed and Azolla are reduced, but what is still there is either dead (a lot of duckweed) or thriving (both Duckweed and Azolla have green healthy leaves, but not many of them.). I have lost a lot of the Azolla, and I do not know where it is. Gone.
Hornwort probably won't come back.
Added dechlor (Sodium thiosulfate- does not lock up ammonia)
Added 2 tablespoons baking soda directly into the flow from the filters. Slowly. I think it dissolved almost instantly.
Trace minerals. I used Seachem Cichlid trace, intended for Rift Lake fish. I have used it before and seen almost no response from the tests. It does have a very low level of Ca and Mg, and has many of the trace minerals plants need.
Tests done within a few minutes of filling:
KH 5 German degrees of hardness. Tap water about 3, added enough baking soda to make it closer to 7, but tested so soon it was probably not well distributed. Will test again tomorrow.
pH 7.8, tested with 2 different tests. Note that this is lower than the tap water that I just added. The test (API high range) was really different, and so obvious that it is not 'user error'. I read the results right. The other test (a lab quality pH strip) agreed.
TDS 270 (Higher than the tap water, but seeing all the stuff I added, I am not surprised.)
Ammonia 4 ppm.
Chlorine was neutralized right away, per 3 different tests done a few minutes apart.
Tests done about an hour after tank had been refilled, water circulating:
Nitrite: 5 ppm. Hm. Hm. mmmmmmmm. Maybe the last test where it was WAY off the chart was really WAY off the chart? Then even though I got rid of almost all, there was some clinging to the substrate, and is now in the water. Darn, I hoped it would be lower.
NO3: under 20 ppm.
pH 8.4 per 2 tests (Gosh, back up again- glad there are no fish in there!)
KH: This was tested with the strips, and showed higher than I would have thought, between 200-300 ppm (= 11-16 degrees) Hm. I wonder if the pond 'tablets' have dumped another dose into the water. They sure got stirred around when I put the rocks in.
GH = 100 ppm = 5.5 degrees. (All my other GH tests are old, no longer work, so this strip is the only way I have to test it)