melev

As you know if you follow my blog, I share the good with the bad. I hate admitting the bad, because people often put my up to higher standards and I already set my own standards quite high, but here's the scoop:

The staghorn coral continues to STN slowly from the base up. And a couple of other spots of white appeared in about three more corals. I kept testing, trying to find the cause. When I tested nitrate this week, they were off the chart. Since that doesn't match what I measured three weeks ago, I retested. Still blood red. Looks like I found the cause, because most Acropora do not like nitrate.

When I get a bad reading, my gut says check the livestock. Anemones, LPS, zoanthids all seemed fine. Fish look the same. But yet the white death on my acropora was telling me the reading is likely valid. So why did I get a good reading for so long, and why did I get the bad / true reading all of a sudden? No idea. I ran up to the LFS and bought a brand new nitrate kit, and measured. Easily over 80ppm. I haven't seen high nitrate readings in who knows how long.

I did stop running biopellets 15 months ago. That means denitrification came from the sandbed, rock, refugium and water changes. Which leads me to the other thing I've not mentioned lately, water changes. I'd mixed up a big batch of saltwater some time ago, but didn't measure it correctly. It was way too salty, and I never seemed to have time to drain out a large quantity from the 250g of mixed saltwater to dilute it with more RO/DI water. This week's revelation gave me the necessary motivation. I removed 45g of saltwater that measured 1.037sg and added RO/DI water until I got it down to 1.027sg. My reef measures that at the moment, and I wanted it to be exactly the same since I was about to embark on a series of daily water changes to combat the nitrate level.

For the past four evenings, including tonight, I changed 55g of saltwater per session. This is how much water I can drain from the skimmer and return section of the sump. The first two nights went perfectly. Temperature and salinity were dead on. However yesterday and today, both times a bunch of white sediment emerged from the plumbing clouding up the tank to my dismay. By morning it's crystal clear and the Nyos skimmer is full of white-sludge. Perhaps it was precipitation from the over-salted batch of water, but the strange thing is the saltwater circulates constantly and the first two days it came out clear. Perhaps since the water falls down further than originally, the settled stuff is now in suspension. I'll be glad when this vat is empty, rinsed and a new batch is made.

Nitrates are lower after 220g worth of water changes. I think I'll have to do the same again next week. It takes 2 days for the vat to refill with water before I can add fresh salt, then it needs to mix. Tonight I refilled the carbon (GAC) reactor, and set up the biopellet reactor with 500ml of media. I like running biopellets, and it obviously worked for me in the past when I dosed Prodibio properly. There you have it, my situation and what I did to resolve it.

Here are three pictures from the tank today, the last images of 2015. I used a fisheye lens for fun. I hope to do better next year. Happy new year everyone.