Replacing RODI

[mcarroll]

On 5/21/2022 at 1:53 PM, DevilDuck said:

What?! Really?! I wish I knew this before I lost 2 BTA's. One I lost right before a dino outbreak and another the other was right after after my battle with dinos. Then I started vodka dosing and my new BTA starting declining. This piece of info needs to be framed some place!

Low nutrients in general, and carbon dosing in particular, are strongly associated with coral problems and pest algae outbreaks....surprised that you would face dino's only to begin carbon dosing afterward.  Your corals (their slime) should ideally be your tank's main and only significant carbon source.

 

Anemones are VERY large polyps, and as such have large appetites for nutrients.  (Has even been documented in the literature.)  Stability is part of the necessary equation too of course, but that goes for a reef tank in general....not specific to anemones.

 

On 5/21/2022 at 8:33 PM, aclman88 said:

that 10:1 ratio

Rules of thumb can be handy, but that's a rule of thumb at best...someone's mostly-arbitrary number based (I'm guessing) on the thought that some cyano are able to utilize atmospheric nitrogen when nitrogen is limited in other forms (eg ammonia).   Count how many tanks you can find where that ratio actually applies before you put lots of stock in it.  (One tank is not a relevant sample of course.)  And then also remember that fish are a continuous ammonia source as long as they are being fed.....so most tank-based cyano are not really going to be N-limited even if your test kits show zero nitrates.  (There are many usable forms of nitrogen too other than the ones we test for.  E.g. ammonia acids, etc.)

 

I think that ratio is just another way of saying avoid driving nutrients (nitrate in this case) to zero. 

 

Whatever variant of that advice sounds good and is memorable is good advice...just remember that the goal is not some arbitrary number.  The goal is to have conditions that favor green algae and corals.   (Same conditions for both.)

 

Also, cyano is not very predictable in my experience.  It likes many different conditions....including conditions during an active dino bloom.  

 

Partly this lack of predictability is due to us generalizing "cyano" when there are probably multiple species involved....just as there are with green algae.

 

P.S.  Glad you got your RODI system rehab'd!  Definitely something that gets overlooked or forgotten.  <* ..as mcarroll goes and orders new filters for his RODI. *>

 

P.P.S.  Most of your RODI filter modules are rated for "X" gallons of filtered water.  Sometimes 3000 gallons is common for pre filters and carbon modules....but check the specs on your product – all are not the same.  I forget the gallonage for the membrane, but it typically translates to around 3 years of usage.  DI is probably also rated for a few thousand gallons, but remember that it handles ONLY the product water and not the waste....so the volume of water your DI stage has to handle is that much (your product:waste ratio) less compared with your pre filter and carbon stages.  FYI, if your local store carries branded RODI gear, you would hope that their vendor is spec'ing the right filters for their water....buying local should eliminate a lot of these questions about which filter modules are best.  Certainly worth asking them about....IMO probably worth a small premium in price as well.

[jservedio]

10 minutes ago, mcarroll said:

Rules of thumb can be handy, but that's a rule of thumb at best...someone's mostly-arbitrary number based (I'm guessing) on the thought that some cyano are able to utilize atmospheric nitrogen when nitrogen is limited in other forms (eg ammonia).   Count how many tanks you can find where that ratio actually applies before you put lots of stock in it.  (One tank is not a relevant sample of course.)  And then also remember that fish are a continuous ammonia source as long as they are being fed.....so most tank-based cyano are not really going to be N-limited even if your test kits show zero nitrates.  (There are many usable forms of nitrogen too other than the ones we test for.  E.g. ammonia acids, etc.)

 

I think that ratio is just another way of saying avoid driving nutrients (nitrate in this case) to zero. 

 

Whatever variant of that advice sounds good and is memorable is good advice...just remember that the goal is not some arbitrary number.  The goal is to have conditions that favor green algae and corals.   (Same conditions for both.)

It's entirely a a generalization that is just a nice round and easy to calculate number that approximates roughly the Redfield ratio and actual concentrations on various reefs from around the world when read as nitrate:phosphate. It's easier to quickly do in your head just multiplying by 10 compared to actual Redfield Ratio (12:1), average for Great Barrier Reef (12.75:1), or the Arabian Sea (9.75:1).

 

Basically, just saying you shouldn't let either your nitrate or phosphate get too far out of that rough range where a drastic increase in any utilization would cause one of them to drop to zero (bacterial bloom, algae outbreak, etc.). It's not intended to be a rule, just a rough "hey, my phosphates are super low compared to my nitrates - I should probably fix that so I don't end up with dinos because I had a bacterial bloom" or "wow, my nitrates are really low compared to my phosphates - maybe that's a factor in this cyano on my sandbed."