Long term success without carbon dosing

[asylumdown]

I would start bio-pellets now, if you plan on them being a part of your over-all tank strategy. Many of the cases of biopellets causing crazy cyano blooms (mine included) involved older tanks that were 'higher nutrient' starting pellets midstream. On my old 90 gallon, which was by no means an ULNS, I had cyano so badly you couldn't see the sand or rock a week after starting pellets. On my current tank, which has had pellets from the beginning and evolved from the start with them as a part of the system, I've never had that problem.

Also, I have no data to back this up, only personal experience from a single case (and an anecdote does not a rule make) - but I have a hypothesis that if you end up with a problem algae outbreak and then add pellets to try and control it, you're not going to have nearly as much success than if you start the pellets or some other carbon dosing regimen early and prevent the problem from happening in the first place. My logic behind this is that pellets can only suck nitrates from the water that is flowing through the reactor, while an established bed of algae has the entire surface area of your display tank to pull nutrients from the water column, so once an algae problem happens, they're going to be a better competitor for what does become available in the water than your biopellet reactor. I've never tried whole tank carbon dosing, but it probably doesn't apply in that case, but either way it's better to never let that problem develop in the first place.

The people who've had success with SPS and no carbon dosing long term have something else in their tanks dealing with the nutrients. Unless you do very frequent, very large water changes, that's never going to be sufficient to keep nitrates and phosphates down long term with a medium bio-load, so for the people who only do that and still have sparkling clean, algae free tanks, they likely also have very good live rock that denitrifies efficiently. You can try to cherry pick the best rock, but since you will never know what's really going on inside of it, you really have to rely on luck in choosing the best pieces if that's how you plan on dealing with nitrates long term. Bio-pellets or carbon dosing simply gives you more control over the process.

[asylumdown]

Originally Posted by Son Of Skyline

My tank is a little over 4 years old and at about the 3 year mark I started dosing vinegar and tried pellets. My algae all disappeared, and my corals became pale. I had to clean my pumps and plumbing twice as often because of the bacterial slime buildup. I could tell that all the inhabitants of the tank were stressed to some level. I stopped after 6 months and now everything seems much happier. Better PE, more "normal" algae growth, coral colors deepened again (some more brown but much happier looking), no more slime clogging up my plumbing..etc. I won't do carbon dosing again. My tank never needed it.

What you're describing is a pretty normal response to corals living in a low nutrient environment, it doesn't necessarily mean they're stressed. Some would argue that the darkening/browning of corals is also a symptom of stress. In reality, I think both conditions are simply different possible states along coral's range of possible adaptations, and what we think is 'best' comes down to personal taste. What you view as 'normal' algae growth might be nuisance levels to someone else. Changing the condition that a coral is adapted to will cause it stress, but they're very good at adapting to a wide variety of nutrient conditions given time (within reason). Whether you like 'deeper' colours and are ok with some brown and noticeable algae growth, or whether you like the more pastel 'zeo' look or don't want any algae growth at all comes down ultimately to personal taste.

In any case, having biopellets does not ultimately mean that you have to have an ULNS, controlling the amount of pellets you put in your reactor, or getting a recirculating reactor can allow you some control over the way your corals look.