The initial cycleThis was the beginning of the exciting bit! Once the aquascaping was settled I left the tank for a few days with all pumps and skimmer running and with the lights on for 8 hours a day. Sadly I also spent quite a lot of time rock watching to see any changes in the rock. This was totally different to freshwater aquaria as different lttle critters started to show themselves. After about 5 days I began to notice a brown dusting on the rocks. This was the first appearance of diatoms. This was a bloom of brownish algae covering firstly the rocks then the sand and the glass. The water remained clear and was not at all coloured by the diatoms. Although this looked unsightly I was assured it was part of the normal cycle. At this point I added some cheatto to the sump to help with nitrate reduction. I set the lights to give a reverse photosynthesis regime. I had tested the water and had readings of 0 ammonia and nitrite but nitrate was over 50! I continued to monitor the situation but the diatoms continued for a few more days. As the diatoms began to subside I notice more green algae developing, some was similar to the diatoms on both the rock and sand but there was also growth of green hair algae and some that looked red. The balance of diatoms to green algae changed over a couple of weeks. On testing my nitrates I found this was also coming down to more acceptable levels 25 and then quite quickly down to around 5. Also noticed more life around the rocks. Some little snail like things, a few tiny fan worms and occasional little white brittle stars. As my nitrates were now at an acceptable level I introduced the first of my cuc, some trochus snails and algae or micro hermits. I used a drip acclimatisation method for these. It was actually interesting to see the changes in the different types of algae. Some would be dominant for a while and then others would bloom but thankfully most started to die away. I began to see red slimy algae in one or two parts of the tank. Both on the rocks and sand. This was the red slime algae or cynobacteria that I had been warned about. Where I could I siphoned it off and had a play around with the powerheads as I thought water flow might be a contributary factor. At this time I also began testing for phosphates and found they were rather high. Seven or eight weeks in and water tests were looking stable, ammonia and nitrite reading 0, nitrates below 5, Ph 8.24, salinity 35, temp 26 and phosphates 0.24 and going down. I reckon the initial cycle is over and the tank is now ready for adding further livestock. Interesting article: New Tank Syndrome |