rygh
Guest
A long while back I started a fun thread on algae scrubbers.
Scrubber technology has changed quite a bit since then. Big improvements.
Both in what is available, and how to DIY.
And there does seem to be wider acceptance on using them.
Yet, after all these years of using one, I am really thinking of switching mine out.
A lot of very respected skeptics and experts have worried about problems related
to scrubbers over the years. Some great discussions on that. But no solid conclusions.
But as the title says, my opinion now is that they simply work too well.
They basically starve the corals.
The reason I feel pretty strongly about that is because of a recent experiment
with Calcium Nitrate.
----
Scrubbers are very good at removing Nitrates.
With a good scrubber, Nitrates are usually undetectable. Mine are.
(Warning : That is about the only part of this post that is fact, not opinion)
They do remove phosphate as well, but it is based on the percentage
of phosphate/nitrate in algae, which is not so great.
Look up "Redfield Ratio" for lots of discussion on that.
Recently, I had been having a phosphate problem. Big Cyano bloom.
I was getting rather frustrated with the normal methods, so I took some
advice from someone about the Redfield Ratio.
The idea is that my tank had become Nitrate limited, so to battle phosphate,
you increase nitrates, then the algae scrubber will reduce both.
So I added Calcium Nitrate until my Nitrates were in a moderate / safe range.
And I kept it there for a few months.
Yes - Really - I deliberately added Nitrates to my tank.
Some interesting results.
First, it helped, but did not work all that well to reduce phosphate.
Scrubber produced more algae, and phosphates dropped a little, but Cyano was still around.
BUT: MY SPS STARTED TO GROW
I have very little as it is. Mostly a few stubs I put in for fun that have managed not to die.
They started growing. A little. Not much. But definite growth.
Nothing else really changed. (This was before the sump switch)
And those SPS had never grown before.
So I stopped dosing Nitrates of course.
Remember, this whole thing was about Cyano, not SPS.
I decided it did not do much for Cyano, so decided not to bother.
I figured the SPS was a coincidence or something.
I then did the usual: Siphon out Cyano, more water changes, use GFO.
Cyano is mostly gone now.
Nitrates went back down.
And .... those SPS died ... really.
All those last items should have helped. But it made it worse.
----
So does that test prove anything? - No, of course not.
The scientific method used was HORRIBLE.
No measurements. No pictures. Nada.
I was not even really trying to test SPS growth. It was about Cyano.
And it certainly could have been pure coincidence.
But some other data:
I have never had much luck with SPS. And after all these years, I do know what I am doing.
They don't get RTN. They just sort of fade away.
I am not the only one with this issue. Many others have struggled.
And now that I look at it in this light, those that struggle more seem to have bigger scrubbers.
A lot of the people that grow SPS just fine with scrubbers have small under powered ones.
Mine is on the 4'th generation, and I am a pretty decent engineer. It is a GOOD scrubber.
I am not the only one with the opinion that corals need a certain level of nitrates to thrive.
No scientific tests, but talking to people, there is quite a bit of anecdotal (ie weak) evidence.
But those I talk to know what anecdotal means, so it is worth consideration.
---
At any rate, just sharing my latest opinion.
Scrubber technology has changed quite a bit since then. Big improvements.
Both in what is available, and how to DIY.
And there does seem to be wider acceptance on using them.
Yet, after all these years of using one, I am really thinking of switching mine out.
A lot of very respected skeptics and experts have worried about problems related
to scrubbers over the years. Some great discussions on that. But no solid conclusions.
But as the title says, my opinion now is that they simply work too well.
They basically starve the corals.
The reason I feel pretty strongly about that is because of a recent experiment
with Calcium Nitrate.
----
Scrubbers are very good at removing Nitrates.
With a good scrubber, Nitrates are usually undetectable. Mine are.
(Warning : That is about the only part of this post that is fact, not opinion)
They do remove phosphate as well, but it is based on the percentage
of phosphate/nitrate in algae, which is not so great.
Look up "Redfield Ratio" for lots of discussion on that.
Recently, I had been having a phosphate problem. Big Cyano bloom.
I was getting rather frustrated with the normal methods, so I took some
advice from someone about the Redfield Ratio.
The idea is that my tank had become Nitrate limited, so to battle phosphate,
you increase nitrates, then the algae scrubber will reduce both.
So I added Calcium Nitrate until my Nitrates were in a moderate / safe range.
And I kept it there for a few months.
Yes - Really - I deliberately added Nitrates to my tank.
Some interesting results.
First, it helped, but did not work all that well to reduce phosphate.
Scrubber produced more algae, and phosphates dropped a little, but Cyano was still around.
BUT: MY SPS STARTED TO GROW
I have very little as it is. Mostly a few stubs I put in for fun that have managed not to die.
They started growing. A little. Not much. But definite growth.
Nothing else really changed. (This was before the sump switch)
And those SPS had never grown before.
So I stopped dosing Nitrates of course.
Remember, this whole thing was about Cyano, not SPS.
I decided it did not do much for Cyano, so decided not to bother.
I figured the SPS was a coincidence or something.
I then did the usual: Siphon out Cyano, more water changes, use GFO.
Cyano is mostly gone now.
Nitrates went back down.
And .... those SPS died ... really.
All those last items should have helped. But it made it worse.
----
So does that test prove anything? - No, of course not.
The scientific method used was HORRIBLE.
No measurements. No pictures. Nada.
I was not even really trying to test SPS growth. It was about Cyano.
And it certainly could have been pure coincidence.
But some other data:
I have never had much luck with SPS. And after all these years, I do know what I am doing.
They don't get RTN. They just sort of fade away.
I am not the only one with this issue. Many others have struggled.
And now that I look at it in this light, those that struggle more seem to have bigger scrubbers.
A lot of the people that grow SPS just fine with scrubbers have small under powered ones.
Mine is on the 4'th generation, and I am a pretty decent engineer. It is a GOOD scrubber.
I am not the only one with the opinion that corals need a certain level of nitrates to thrive.
No scientific tests, but talking to people, there is quite a bit of anecdotal (ie weak) evidence.
But those I talk to know what anecdotal means, so it is worth consideration.
---
At any rate, just sharing my latest opinion.
