I have a 2 feet high tech set up (CO2 / light with regular feetilizing regime). Noticed my cherry red shrimps population is dwindling fast but other fauna (snail, oto) are doing well. Not sure if this is due to the PH fluctuation from the CO2? The checker turns green during lights on / CO2 on. Becomes blue in the morning. Is this an indication of PH fluctuation and potentially causing the shrimp death? The shrimps were well conditioned using the drip method at time of purchase weeks ago.