And I am putting this in a separate comment, because it is weird. I mentioned I had a "mini cycle" a few weeks ago, I though from trying to overfeed a bit to raise the nitrates. Well, I never saw an ammonia spike. I thought I may have missed it because I don't think I tested the day before.
WELL... Since then I have gone back to testing at least once a day, if not twice. SO I bought the ludwigia and crypt last night. Yesterday morning, 0/0/10 NH3/NO2/NO3. After planting, digging down into the sub, I tested, 0/50+/10. I am pretty sure that last nitrite spike was after I planted something. So, I appear to have nitrite (not ammonia, nor nitrate) trapped in my substrate? I tested this morning, and if anything the nitrites were a bit higher, maybe the same. Tonight, 0/0/10-20. Nitrites gone. I did go into emergency mode last night, After all that, I added two different bacteria boosters, pit a bit of the Sera fert that has a good potassium content in, and retested the phosphorus to make sure it was still in good shape. Kicked the lights so they ran at full blast for 8 hours. Also this morning I did a trick with a combo of acid buffer and alkaline buffer that can raise dissolved Co2 without changing the pH, in short cheating to raise the Co2 short term.
What this means is, I boosted everything else in the tank the plants need since there was also a nitrogen boost, and they sucked it all out if the water. The brand new Ludwigia looks great too, lol.
But what it also means is, apparently every time I dig in the sub, I dig up nitrites? It's 4"+ deep, I don't feed the tank lightly, but I don't think I overfeed. Have you ever heard of this in a deep planted substrate? A "separate" nitrogen cycle inches down that just hasn't gotten all the way to converting all the way to nitrate? Deep enough so that it isn't being regularly and freely released into the water column? Seems weird to me?