Hello again Edward,
Thanks so much for addressing the issues that I'm facing. I apologize for not getting back sooner, but I had gone to Grand Cayman for a week to SCUBA dive.
However, I am somewhat confused by your recommendations. You mentioned that if my tank water has a pH of 6.6 and a KH of 9 that I would be looking at 68 ppm CO2. I went back and re-read the information on this relationship just to make sure that I wasn't mistaken, but it seems to me that you have not taken into consideration other buffers, such as phosphate, in the tank water that skew the relationship. That's why I put in the drop checker with 4 KH water. As I said before, it always indicates anywhere from light green to almost yellow. I have read where many other people no longer use drop checkers (or never even started), and simply watch their fish for signs of distress. I have
never witnessed a single fish gasping at the surface as I have read that so many others have had happen when their CO2 levels went too high. I have intentionally checked at all times of the day just to make sure that the fish are always okay. The only reason that I bumped up the CO2 levels was to try and irradicate a large amount of BBA without having to use chemical warfare (Excel). I also haven't noticed my plants being tall, long, and unhealthy, although I'm probably not the best person to ask to judge proper plant growth. I just updated my journal with current photos, so maybe you could check them out and tell me what you think. The plants aren't really growing all that fast, but they seem like they are doing okay to me. The only exceptions are the Hygro species, which seem to be doing better since modifying the PPS pro recipe. In fact, I'd say that the polysperma is almost back to normal, and the corymbosa appears to be finally growing again. It's not that I don't want to lower the CO2 levels; I just question whether they really are too high.
To answer your question about the KH of my water, there are two reasons why it is high. The first is that I use well water, which when I measured the KH of it some time ago, I came up with a reading of 4 degrees KH and 5 degrees GH (for all I know it fluctuates, but I don't check it regularly). It also apparently has high levels of CO2 naturally occurring which causes the pH to be low (I have measured the pH coming out of the well to be anywhere from 5.7 to 6.4). This low pH was causing the copper pipes in my house to be eaten away, ruining all of the seals in the faucets, and leaving blue-green stains in the sinks. Therefore, several years ago I installed an acid neutralization system that all of the water for the whole house goes through. According to the company that I bought it from, it has two different materials in it: Calcite (which they said is calcium carbonate, CaCO3) and Corosex (which they said is magnesium oxide, MgO). Once the water goes through this system, it ends up with a neutral pH, 10 degrees KH, and 11 degrees GH. When I do water changes (which I do typically once a month, and change 30% to 50% of the water), I bypass the acid neutralization system and use straight well water. However, when I top off the tank, I don't bother doing this and just use the water that has gone through the system. I only top off the tank when it has evaporated down to the bottom of the trim at the top of the tank, and I usually only have to do this once a week to sometimes once every two weeks.
Now, for another update on the levels in the tank. As of November 29th, I had 22 ppm NO3, 1.05 ppm PO4, and about 20-30 ppm K (still not exactly sure what LaMotte means with this test, but if I had to bet, I would say that it would be 20, but I'm not positive). I'm pleased that the additional KH2PO4 raised the PO4, even though it actually went up more than I guessed that it would. Yesterday I decided to mix up some more macro solution, but this time I dropped the KNO3 to approximately 14% of the normal recipe, and again went with 200% of the normal amount of KH2PO4. I left everything else the same. I'm wondering if getting the NO3 down a little bit more will help the Hygros do even better.
Today the LaMotte iron test kit arrived. When I tested the water in my tank, I came up with a reading of .7 ppm!! I think that the Mayaca fluviatilis is doing okay, although I'm not positive if it is as "lush and green" as it should be. It's not really growing as fast as I was expecting it to, but that's actually okay with me. Here's a picture of it now (note that I haven't trimmed it after my vacation yet):
Since the iron is so high, I decided to drop the amount dosed to only 33% of what the normal recipe calls for. I'm curious to see what that does. Ray-the-pilot - I know that you said that you had dropped to 40% of the normal dosage and that it had been working for you. Are you still dosing at that rate?
Thanks,
Andy