I can't justify letting this thread die until I post my results. I will post these on both of my favorite sites.
Early this month I noticed a lot of green film algae on my glass. Some of my SPS corals were showing STN. I decided to put my old POS skimmer on line until I can get something better to replace it.
I think there are some contributing factors to consider in addition to the fact that there was no skimmer.
1. I had a 7" hippo die and decompose without my noticing it. That fish was the last of about 4-5 fish to be killed by my purple tang. I removed the Purple Tang and sold it to a reefer with a much larger tank and more competition.
2. The impeller in my kalk reactor pump broke 3 of its 5 fins and ceased to function. I had been monitoring pH as a sole means of determining the output of the kalk reactor. It remained at a stable pH of 8.2 I do not normally test for calcium or alkalinity. - I also noticed the growth of hair algae in my sump during this time.
In all I think it was a good experiment because I was able to walk away with some knowledge. Here's what I learned.
1. 30% water changes once a week is too much new water for an established system.
2. 30% water changes once a week is a pain in the rump.
3. The water is too hard when done in this way. You can actually feel it. A skimmer allows for a slower build up of nutrients over a period of time, enabling the hobbyist to make smaller changes in the water parameters with each water change and allows for less frequent water changes.
4. Detritus or Pulverized Organic Matter (POM) is good food for coral polyp extension. Dissolved Organic Matter (DOM) is not. I will continue to avoid mechanical filtration for this reason.
5. As much as I hate doing it, I need to test my calcium, ammonia cycle components and alkalinity on occasion and especially when things don't look quite right.
6. Count your fish!!! Just because it's been in the system for three years and looked healthy yesterday doesn't mean it won't die tonight.
Happy reefkeeping.