My midnight purchase

fuge_PC,
originally uploaded by Hongyee.

A clip-on 11W power compact light! It's meant for my sump (the extra tank below the main tank, in the cabinet - meant for hiding all the unsightly life support system of my tank). It's now shining right above this compartment of 1-3mm sand, will be planting some mangrove seedlings and Caulerpa macroalgae for nitrate export purposes soon. Hopefully 11W will be enough to maintain the plants.

Piping's still a little messy. On the right (the cannister-looking thing) is my Sander venturi protein skimmer, see the fine bubbles in the riser tube? And the collection cup at the top - full of black nitrogenous compounds that would have otherwise broken down in the tank. It's a lovely piece of equipment, but pales in comparison to the new needle-wheel and beckett skimmers.

On the left's the expensive 1-inch threaded hose I bought, and on the posterior wall is the T-junction where 25% of the pump1 output goes to the chiller and the rest goes back to the tank.

Flow direction's from right to left - water from the display tank above overflows into a pipe which flows by gravity to the right side of the sump tank. On entry there's a coarse filter floss to catch large particles, then the skimmer gets the undissolved organics out, the little white bag on the right's my phosphate-exchange resin to remove inorganic phosphate. Unbound phosphate is precipitated out by daily addition of kalkwasser (calcium hydroxide) and removed by the skimmer. Water then passes through the deep sand bed in the middle where denitrification occurs (nitrates into nitrogen in the anoxic deep parts of the sandbed), then the 2 return pumps on the left pumps the water back up into the main tank. There's where all the pipes and hoses come into the picture.

Still need to tidy the sump up though, but maybe during the 1-week break. Going to be a lot of hassle, since I'm planning to add a few union valves and gate valves to the hoses for better velocity control.