Does Macro require harvesting?

[papagimp]

I'm currently battling a severly elevated nitrate problem in my tank (80+ppm). This occured over the course of about a week, from my normal 0ppm levels. One option that popped into my head this morning, if the macroalgae in a refugium (cheato) is not harvested does it still provide the appropriate nutrient export? Or will the nutrients eventaully be leeched back into the tank? The reason I ask is that I have not harvested any of my cheato in awhile, I've been letting it fill up the majority of the refugium space. Bad idea? Not going to matter? Thoughts?

 

[graveyardworm]

You are not exporting nutrients until you remove some of the macro. The macro binds the nutrients until it is harvested, or begins to decompose. So as long as the macro is growing its continuing to bind nutrients. The larger it gets the more mass it has to grow and bind nutrients.

However if the cheato ball becomes so dense that light and water flow is no longer reaching into it then that portion may no longer grow and may even begin to decompose. Also detritus can build up within the ball and may actually add to nitrates.

What I do is about once per week I fluff and turn the ball to keep good water flow and light penetration, and to shake out some of the detritus so that it doesnt build up.

 

[papagimp]

exactly the information I needed Graveyardworm, thanks a bunch.

I usually don't mess with the cheato, other than turning it over every few days. I have a massive stometella and grammarus population and they actually do a great job keeping detritus buildup off of the cheato ball. Love those little buggers!

 

[reefgrief]

The question is.. what is causing the Nitrate to run so high ? So more info would help.. 1) do u have more than 4" of sand.. 2) how much live rock is in the tank.. and did u just put some uncured rock in ?
3) Do u have sand in the sump/refugium with your cheato ?
4) What is your fish/ coral load like ? Too many fish invite overfeeding.. I 've been guilty here way too often, and removed my bigger fish to a third fish only tank.

in my oppinion, having a deep substrate helps denitrifying bacteria do their job, and that means high nitrates, so removal might mean water change (short term) and keeping a big mat of cheato present to bind the rest. Probably other ideas will work just as well.. hope you can get more feed back

 

[graveyardworm]

in my oppinion, having a deep substrate helps denitrifying bacteria do their job, and that means high nitrates

One of the purposes of a deep sand bed is to lower nitrates. Just like with LR there are bacteria which live at the lower depths of the sand which convert NO3 to to a gas form at which time it is able to leave the aquarium without any manual removal on the part of the aquarist.

 

[reefgrief]

So along with bacteria that reduce Nitrites to Nitrates.. there are bacterial oxidizers which take Nitrates (like KNO3) and convert them to NO2 gas ?.. Perhaps they don't actually use oxidation. (O2 is not gonna penetrate a deep bed easily.

But now I am curious. What bacteria convert that ion to a molecule? I was thinking that other anaerobic bacteria converted the nitrate to amines for protein production.. and any unconsumed nitrate because of a poorly developed population, dissolved out into the water. This growth of bacteria and their slime production result in the need for a skimmer.

Am I way off here ?

Any way, I learn something new everyday.. I need a follow up on just what is happening..

Thanks for the input!

 

[aggie4231]

Heres a link to explain the Nitrogen cycle.
http://ghs.gresham.k12.or.us/science/ps/sci/ibbio/ecology/notes/cycles/nitrogencycle.htm

Surprisingly, When I searched, Nitrogen Cycle in the Aquarium, on google, none of the results included the denitrification portion of the cycle.

 

[reefgrief]

Well I remember that cycle for bio years back.. thats why I was thinking denitrification was an aerobic ( requires deep bed) and nitrate oxidation to NO2 occured in oxygenated water.. Maybe I still dont get it ..

In any case if high Nitrates are in aquarium water...Some bacteria are insuffient to get rid of it.. so adding more live rock and perhaps an air stone in the sump would help..

I was hoping to help here.. but not sure I am doing much more than confusing the issue
So if I have made a moron of myself.. just laugh.. a good chuckle wont hurt anyone

 

[graveyardworm]

No one here is a moron, we're all learning.

Adding more LR, is likely to set off another cycle, which will only add to the nitrates, unless the LR is fully cured/cycled.

Chances are O2 in the water column is not an issue, so the likely hood that an airstone will raise the O2 in the tank to a level which it adds more O2 to the deeper layers of the sand bed is unlikely.

A few theories on why the nitrates are so high.

1) more imports( feeding, topoff water with excess nutrients) than than exports ( skimming , water changes, macroalgae removal, malfunctioning of DSB( if there even is one), not enough LR).

2) Problems with nitrate test kit, resulting in false results.

 

[3D-Reef]

There are several types of bacteria at work in this whole process.To start you have heterotrophic bac' turning waste into NH4 mineralization.
Then you have autotrophic bac' turning NH4 to N02 and then to No3 nitrification.
And then there is the anaerobic bac' converting No3 to N.Called, denitrifying.
In a low 02 environment the bac' use the o3 off the No3 for their o supply.demineralization