High nutrient levels with chaeto and biofilter only

[krayziez]

Hi guys, I'm wondering if it's a good idea to have my tank be on "high nutrient" while satisfying the elimination of a high nutrient condition's byproduct of phosphates and nitrates. Basically, I want to have a tank for mostly filter feeders, xenia's included, and I've noticed that my xenia's don't do well when my water is crystal clear (including no nutrients). My theory is alot of soft corals will do well in high nutrient waters because they absorb the nutrients and most or all filter feeders including some sps will benefit since they have tiny mouths. Phyto and zooplankton is what I wanted in my water to constantly feed them so having carbon and skimmer might clean the water too much.

I wonder if having just a crapload of chaetos and MarinePure biofilter will turn all that ammonia/nitrates into free nitrogen. Basically, I want to have the food go through the complete cycle instead of it being eliminated half way where the corals could use the nutrients. I heard having lots of chaetos will out-compete any algae blooms. And BTW, will chaetos absorb the phyto/zooplanktons?

OR I could do it the old fashion way and just filter out everything and just do broadcast feeding and let the skimmer/carbon take care of that within a day but it seems like I'm just wasting the carbon by using it to get rid of the phytoplankton that I just introduced, basically collateral damage.

 

[rt67ghy]

Theoretically it can work but it depends on factors such as how much you're feeding, how often and how large the WC you're doing, whether you vacuum the sand, how big your fuge is, how much chaeto it can hold and how much MarinePure you can fit in your system.

I think this would be a great idea if you have or plan on having a lot of NPS corals, gorgonians and filter feeders as well as LPS corals but I'm not sure if acros and montis will like it. To have success with acros you need to keep the water clean.

Chaeto won't directly absorb the phytos/ zooplankton; they could only incorporate the NO3 and PO4 after the bioplogical breakdown of the excess food/ fish waste.

As to the chaeto out-competing the algae/cyano you'd have to strike a balance and provide a lot of strong lighting for its growth for long hours while making sure the NO3 and PO4 are low. Otherwise the algae/cyano will grow in spite of the chaeto.

However, I think there's no harm in trying and letting us know what happens.:lol:

 

[Reef Frog]

A mature tank with porous live rock will be the most efficient in converting nitrates into nitrogen gas, due to the specialized bacteria living in those spaces. The food volume you put in the tank will depend on fish load and how much/if you target feed corals, and that will drive your nutrient levels, minus your export mechanisms.

I don't know about softies like Xenia, but GSP, zoas, Florida ricordia, mushrooms, clove polyps etc do indeed seem to grow & reproduce much better in "richer" water when compared to a tank that is lightly fed, with no or few small fish, highly skimmed, with GFO & GAC reactors chugging away for 24/7 for example.

Many stony corals seem to grow faster with better coloration with traces of nitrate & phosphate in the water, but it's easy for the pendulum to swing too far where you have pest algae running wild which can smother them. It is well known that excessive phosphate levels interferes with skeletal growth.

It seems plenty of people on RC run high nutrient tanks with minimal export. Sometimes it's hard to tell how well this strategy actually works over the long term with virtually no export however. Usually some export is necessary, even if it's simple as a water change & removing excess chaeto once in a while. I'm sure such tanks are pretty good at accumulating unsightly detritus as well.

I'm sure the approach you describe can be done successfully, but a balance must be achieved and that is likely to take some time & effort.