Just looks like the beginnings of GHA to me but maybe I'm not seeing something. Something isn't right with your numbers. Alk shouldn't be that high with Ca that low and Mg in the sweet spot. Are you dosing anything? The reason your Ca is low is because you are mixing your salt to 1.023. Mixing it to .025 to 0.026 should get you above 400 and hopefully in the 420 to 440 range.