More Hungry Corals, Easy Water Changes, and the invasion of the Vermitids

Water quality was iffy for a while there. I discovered that the little blue sponge between chambers 2 (refugium) and 3 (main pump) had become dislodged and was floating around chamber 3. Its only real function is to prevent anything floating around in chamber 2 from getting stuck in the pump. Without it, however, the tank had zero mechanical filtration of any kind, and particulate quickly began building in the water column... one of the byproducts of having high flow throughout the tank is that nothing really "settles". Even the sand is slowly carried around the tank in small dunes by the current.

I left off last time with a possible avenue towards better mechanical filtration and put that plan into action this week. I bought a large roll of polyester filter floss (making sure to use the non-treated kind; some have flame retardant chemicals added) and placed a square piece of it it immediately after the overflow from chamber 1 (intake, heater) into chamber 2 (refugium). This floss is resting on the previously unused drip tray. By keeping the water level at or near the top of chambers 2 and 3, the refugium is always full and water doesn't make a loud dripping/trickling sound as water flows into chamber 2. It's also a little easier to see the proper water level which means RO/DI top-off is easier and more accurate- combating evaporation and therefore increased salinity is a daily or every-other-day task. I used some waste water from my last change to scrub clean the blue sponge. It shouldn't be doing any major mechanical filtration from now on; that is the job of the filter floss. Cleaning the sponge turned the waste water in the bucket from an off-light-yellow to a nasty dark yellow. Below is a picture.. check out how much the filter floss collects in just a couple of days:

I also revamped my water changing method. It's one of those things you simply have to do in order to keep more demanding species and maintain a stable environment. I now have an extra 50watt Jager heater and a Maxijet pump which heat and mix water in a dedicated bucket for a couple hours prior to weekly 15% water changes. The bucket allows me to mix my RO water and salt water to the proper salinity; about 1.021 or 1.022 specific gravity at ~80 degrees. Specific gravity is also a function of temperature, so measuring a cold bucket of water will yield inaccurate results.

I attached a long clear rubber tube to the Maxijet output and use it to take water out of the tank into an empty bucket. When I've taken enough out, I switch it around to send water back into the tank from the fresh bucket of water. When refilling, I have the tube send water into chamber 1 of the tank where it flows backward (through the intakes) into the tank without disturbing sand or corals.

It takes some time to heat up ~5 gallons of water from room temperature.

If you remember the Q = m · C · ΔT equation from basic chemistry, you can do some napkin math to approximate how much energy and time it takes to heat the bucket and how long a 50 watt heater would work to do so. 5 gallons of water is 18.93 liters, and at 1.022 specific gravity (kg/liter) that's a mass of ~20 kg. The specific heat of fresh water is 4.186 Joules/gram·degree Kelvin = 4186 J/kg·K; sea water is a bit less at about 4000 J/kg·K. Let's say we are raising the temperature from 70° F to 78° F: that's a difference of 4.4° Kelvin. Doing the multiplication, it's 352,000 J of energy to heat up the water. The 50 watt heater, if 100% efficient, puts out 180,000 Joules/hour, so it will take about 2 hours to finish the job. There are many other factors like loss of heat to the container/environment and evaporation, the heat imparted by the Maxijet pump, etc, but it is good to have some idea. In any case you can just put on a movie and wait until the light on the heater switches off which is my preferred method.

So enough boring stuff- where are the new corals?? I've got three interesting additions to the tank: A red and orange Acanthastrea lordhowensis. ("Acans"), a Duncanopsammia axifuga ("Duncan"), and Cyphastrea ocellina aka "Meteor Shower" which my LFS fragged for me gratis. Very nice of them. The Meteor Shower is a quick grower and I've affixed it to the contoured white live rock on the left side of the tank where it will quickly spread. Later I can remove the glued frag and put it elsewhere to propagate. There may be some eventual conflict with the small purple clove coral that is also spreading on that rock... something tells me the Meteor Shower is going to win that battle. The rock in question has gone from bleached white the first week to lightly browned with diatomaceous growth, to a smattering of purple as the coralline algae begins to grow all over it. Maybe my PurpleUp is working.

Acanthastrea lordhowensis

Duncanopsammia axifuga

Cyphastrea ocellina

When I glued this to the rock, I had to press hard on the end of the coral- 

wearing off some of its purple material and damaging a polyp. It will grow back in time.

The Duncan has three large heads on it and that's what I paid for- but when the heads close, there are seven heads easily visible (total)... four of them simply hidden below the large crown of nematocysts on the parent polyps. They'll soon grow out into a waving hemisphere of green tentacles. Great deal! The Acan had been fragged and looked a little bit haggard but within a few days it has puffed up and is regrowing its skeleton where it was cut during the frag process. I've heard that these are very hardy corals; their unusually high price is a product of exportation law, popularity, and hype. Both the Acan and the Duncans are fed Mysis on the same schedule as my Lobophyllia open brain. Fortunately the Duncan is a very quick eater and doesn't needed to be shielded like the Dendros. Both are in the same family: Dendrophyllidae.

Happily stuffed full of mysis.

I've decided to give back or trade in several of my hermit crabs. They are more trouble then they're worth, I think. A couple of snails in their place will do more good work in the tank and probably inflict less damage on fauna in the sand and on the rocks. I'll leave 2-3 of the smaller ones in the tank for kicks.

Nefarious hermit crab with innocent expression.

Back to water quality- I've now got a tennis ball sized clump of chaetomorpha algae growing in my refugium... another freebie from the LFS (another customer of his brought in a whole bucket full of the stuff). I'm hoping the growth takes off and it begins consuming a lot of the excess nutrients in the tank. Once this small clump grows to take up the whole refugium, I'll clip half of it and trade it in for something. This is called nutrient export and is only one half of combating nuisance algae; the other half is limiting nutrient import. Overfeeding is the number one cause. I'm going to try something that I recently read on WetWebMedia, one of the best sites out there for question and answer format info/research. A guru was answering a question about mistakes which lead to out-of-control algae growth,"like thawing frozen foods but not decanting the thawed pack juice which is "rocket fuel" for growing nuisance algae, sponges or Vermetids in this case". Sounds like a great idea. That liquid is very rich but doesn't really do anything for the organisms that I'm actually trying to feed; in this case fish and corals. It is, however, scarfed down by algae, planktonic creatures, and the subject of my research the past few days: Vermetid Snails. Here are three on the same rock as my Ricordea.

These gastropods that are essentially snails which plant themselves in one spot and grow onto the rock. Their shell is fused to the hard surface and slowly grows up and away from its base. The snail peeks its head out and to feed, releasing a relatively long line of sticky mucus which collects particulate matter, and retracts this mucus to eat whatever it picked up. This mucus can aggravate corals in the vicinity and, let's face it: looks like snot. At first I welcomed these novel hitchhiking creatures assuming that they were an acceptable part of the ecosystem but the more I read about them, the more I want them gone. They can and will grow in tubing and eventually clog it; they can and will bother corals with their mucus and corals will grow around them; the ends of their calcareous tubes are almost always razor sharp and can slice open a hand; and they reproduce like mad under the right conditions... the list goes on. They can be controlled by having good water quality and low nutrients/particulate matter but I think I'll be handling this population primarily with needle-nose pliers... at least the ones in near vicinity of my corals. I already see baby vermetids growing on rock that was formally barren, which means they are flourishing in my tank. Better deal with them before they become a problem.

My fish remain quarantined. They're well; active and eating, but it seems a crime to have them outside of the tank for so long... looking forward to mid January! The goby is still sullen but has learned, like the clowns, to eat mysis directly from the feeding baster. Days until reintroduction: 26. Seems like forever.

Bummed out goby.

The Mexican Turbo Snails have been doing a stellar job. They aren't yet big enough to bulldoze rocks but they have almost knocked over a frag right before my eyes. I need to position the frags that aren't yet glued so that if they are knocked over, they won't land on another coral and sting/get stung. Corals coming into contact is generally a Bad Thing.

Note the amount of pods and assorted microfauna in just a few square inches of glass in the above photo. I finally got a great picture of the copepod population on my glass. I'm sure their booming population will come into check when there are fish in the tank.

Another big update coming soon!