That's a relief!! I thought something was going wrong. I don't have a secchi disc, but I will make one today and check the clarity. I am sure I will not be able to see down to 12 inches. I have a submersible pump with a fountain head that I thought was all I needed for aeration, until I started reading this forum. I have ordered an economy air station from Forever Green and it is being shipped today. Hopefully that will take care of any oxygen depletion. Will the pond remain green? I will post again tomorrow and let you know what the secchi disc results are. The days have been very hot here in southeast La. with a fair amount of rain. How long do you think I have to get the aeration system installed before before I face an oxygen crash?