Loading ...So now you know what Slow Tissue Necrosis is and what it looks like. As well, you now know what to look for when analyzing your sps corals. In part 2, we touched up on what to avoid and what could cause your STN events. Things like salinity swings, temperature swings, alkalinity drops and ultra low nutrient systems are to be avoided. But, if you are subjected to any of these occurrences, here are some of the things you can do to rectify your problems:
Temperature Swings:
If you are noticing that there are frequent swings of 5-10 degrees F, you need to implement a some sort of a control device. Best for that would be either a specifically designed temp controller, such as.. or a system controller (the likes of Reef Keeper or Profilux). In the winter months, many of us use heaters to keep up with the heat demands. Most heaters have a controller on their own, but can often fail with wear. Equivocally during summer months, your heat can rise and is in need to be cooled down. Many hobbyists employ fans, which are directed towards the surface of the water. Some use chillers, which require a lot of electricity to run. With a system controller unit, you can tell the heaters to turn on or off, with very small hysteresis(variance), and vice versa with your fans/chillers. Your temperature will be stabilized this way, and will not fluctuate during the day or night.
Salinity Swings:
The most important aspect of keeping stony corals is keeping the salinity levels at a steady mark. The best tool for keeping your salinity in check is to use a Auto Top Off (ATO) controller, which employs light sensors. These sensors tell the controller to dump more fresh RO water from your storage container. Now, if you want even more stability and piece of mind, allow the system controller (like a Profilux or RKE) to oversee the work being done by the ATO. In a case where the sensor fails, the system controller can override the ATO. It can pump or shut off a pump in an emergency within seconds. You can monitor your salinity digitally through a system controller, and set the desired levels based on your needs. Fluctuations will be a thing of the past.
Alkalinity Drops/Jumps:
The one thing that can be easily unnoticed is your alkalinity. If you have either a calcium reactor, kalkwasser reactor or a dosing unit, the rate of which you add alkalinity can change quickly. Either your effluent/intake line can get clogged, your kalk ratio is out of balance (high concentrations), your uptake of alkalinity changes by the livestock additions, etc. There isn’t a real way to control this, outside of using a steady dripping mechanism. The only way to sure know how to meet your system’s needs is to perform day-to-day ALK tests using a kit. Once you feel satisfied that you drip rate matches your uptake rate, the swings will be minimal and tolerable.
Avoid adding buffer in one shot, when trying to stabilize your pH (or ALK). A lot of hobbists combat the swings in pH by adding a bicarbonate product, such as the Baking Soda. The relationship between ALK and pH is positive, so if you enhance one parameter, the other will be enhanced as well. So be careful, as that could cause an STN event.
ULNS (Ultra Low Nutrient System):
Corals need nutrients to grow. They need light and they need food (zooplankton). So when you strip them from nutrients, you allow them to be in a very weak state. Only through additives, such as Amino Acids, Essential Elements (Potassium, Iron, Bromide, Strontium, etc, etc), are they allowed to gain their health back. So why even go that route? But not to digress, if you are subjected to this kind of environment, think about polluting your tank. You are probably thinking that this is a crazy idea, and one that is not shared by many. But, it is true. By adding Nitrogen (or Nitrates in this case), and Phosphorous (or Phosphates), you are giving what the corals need for growth. In small amounts, these elements are necessary in water. It is only through excess that we see overgrowth from algae. So feed your tank! Feed the fish, feed the corals. Add proteins, like fish eggs, silversides, mysis shrimp. Don’t thaw your frozen food for a time period. Let those phosphates into your water. Throttle down on your skimmer. Let the skimmate come our very thick.
Do this until you notice that your refugium macroalgae is starting to take off. You chaetomorpha should be in a growth spurt. That is a sign to slow down, as your nitrates are elevated. Some say in the meantime to dose Potassium and Bromide (ZeoVit sells K-Balance and B-Balance). They aid in restoring the health and color of corals. One indicator of low Potassium or Bromide is the loss of color in montiporas and blues/reds in acroporas. Look for this key when thinking about adding Potassium and Bromide. If you are unsure of adding this stuff, just complete a 25% water change, and that should take care of some of your needs.
But sometimes, you may be required to shorten your photoperiod, as the corals in this mode are more sensitive to light.. especially when they are irritated or depleted in nutrients. High light can cause an STN event, so be careful.
If you have your story to tell, or want to share, please make your comment below. We would love to hear from you, as I am sure many of your have encountered this problem. All of us can learn from your story.
Related posts:
- STN and The Real Issues, part 1
- STN and The Real Issues, part 2
- Controlling Your pH
- Long awaited release of the ReefKeeper Elite (RKE)..
- Photoshopping Corals 101
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Trained by the thirteenth ring master of the Sian Xiuang Coral Temple. Currently is apprenticing the art of Acropora shaping in the ancient tradition of Ninja Fragging. Known as the SPS hero!
Interesting reading. Question; wouldn’t GSP, Zoa, Paly, leather show signs of distress and lack of growth in a ULNS environment that went over the edge?
I would assume, because of the Acropora die-off, the water would be polluted enough for them to be alive. But in time they too would be affected. As well, I don’t think the need for elements is the same between the different coral groups.
I love these sps stuff, just keep them coming
Do you see why we love them so much?
Frankly no
But this is one of the non-clownfish thing I like to read more from the experts here.
Love/Hate relationship for me. When things are good I love them, but when things are bad it’s really baaaaaaaaaaaaad! Keep up the good work guys, always thought provoking reading here.
Interesting reading… my only question is why people report increased coloration when using zeo or vodka or other low nutrient systems? Is this simply because of the other things they dose? If so, why should the color be different than when not using a low nutrient system?
The lightened color is due to corals expelling the symbiotic zooxanthellae. In my opinion, this look is achieved by starvation of corals. It is a stressed out look. Only through additives that these corals are allowed to continue to survive.
so the pastel colour are all cause by stress colour? like light pink, light blue
If the overall color is pale, or washed out.. very light in color, then yes the coral is stressed out.
so you are saying that all those zeovit.com showcase tanks with very light color sps are all stressed tanks?
This is the first time I hear this hypothesis though.
No they are produced by the system (zeo). to keep them that colored and growing, they have to constantly add supplements.
Like I said, its a great marketing train.
I’m now going through a heart-breaking STN episode (but thank God it’s not RTN!). My K is low (280) although the accuracy of these hobby tests is questionable – a friend of mine got the same reading and he has no STN. I can’t measure the Bromide though. Anyone know a good source of Bromide available over the counter? I’m willing to experiment dosing various stuff in order to determine what’s causing this.
Has anyone linked STN to poisoning by heavy metals or anything else? I have been keeping a rusty fan over the tank… and also some decaying rubber bands in the water!
What about the use of phosphate removing media? Could that have triggered STN as long as hair algae are still present in the display tank? (meaning that phosphate is not zero)
My NO3 is around 3, kinda low, but I do feed corals daily.
Funny thing is that some acros grow like mad and are well coloured while others don’t grow, get STN from the bottom-up and sometimes even from the tips down. In fact even the sick ones are coloured; it’s only recently that some branches have started showing that morbid brown that foretells death within a day.
It could happen with heavy metals, such as copper. But having a rusty nail or a rusty blade in the tank will not cause an STN event. While PO4 removing media can induce a slight case of STN if the phosphates are removed from solution too quickly. I would suggest to force a slower flow through the media chamber.
Are the polyps out on these corals?