300 gallon "Outside Corner" Reef

[Gregcoyote]

Yes, I decided to try the reactor Carey recommended. So far it's a churning little beast. I like how GFO targets phosphate. That's what I want to lower a bit. My nitrates are at zero, so pulling more phosphate out thru biological process's are pretty well at saturation. Still have a tiny bit of phosphate I want to get rid of and GFO works well for that if I can overcome the clumping issue. I have grown suspicious of Phosguard. Don't know why, but I have read some reports that question it's safety over tried and true GFO. But then I am rarely happy with not testing theories, so there you go.

Phosphate went up only 4/100ppm so I think the effect hasn't settled in yet, it does have 500+ gallons to deal with. If it still isn't trending down by the weekend I will be concerned.

 

[Sniperhank]

It'll be interesting to hear. One of my concerns with gfo is the hinting of it being involved with clams struggling and pinched mantle. I'm not sold, but I did have to dip both my clams when I was running gfo... Who knows, I'm just clam paranoid at all times.

 

[Stlrockguy]

I've been running phosgaurd and my phosphates are at .12(Hannah checker). Do you think the gfo would get it lower. Nitrates are 0(API).

 

[mr_X]

Aren't you at all concerned having zero nitrate? Do you think such clean water is starving the corals of nutrients?

 

[Sniperhank]

The 0 is relative...the algae I grow is evidence of them existing though the tests always report 0. I believe that is a chunk of the issue with some creatures being difficult to care for, such as the coco worm. Put something in a ULNS (ultra low nutrient system) and there is just nothing to eat! The coco worm is supposed to be difficult to care for, yet in my system it has gone for almost 2 years now, I believe since I lost count really, without any spot feeding what so ever and is still very quick to retract and hide from my mag float as it goes by.
I might be wrong in my assessment of the other systems in this discussion, but believe it to be so.

 

[Gregcoyote]

Natural seawater has a average PO4 of 0.07ppm. Tests on acro growth show best color at about this value, at a PO4 of 0.10ppm or a bit higher there was a browning of the corals because of excess algae production, but they grew even faster. As Doug mentioned, below about 0.05 they can start to starve out.

 

[Gregcoyote]

I've been running phosgaurd and my phosphates are at .12(Hannah checker). Do you think the gfo would get it lower. Nitrates are 0(API).

I don't think there's a down side to trying it. Phosguard works quickly but exhausts quickly as well. GFO has more capacity to bind PO4 but it works slowly. But as the following articles point out we may be chasing a ghost.

Here is a really interesting piece;

http://www.reefsmagazine.com/forum/...g-ix-test-kits-chasing-numbers-phosphate.html

http://reefkeeping.com/issues/2006-09/rhf/

 

[Gregcoyote]

Okay, this is odd. Set up the reactor and filled it half way (about twice what I should have put in) with high capacity GFO. Got it tumbling in a nice gentle boil. Put a cotton filter sock on the output to try and catch any fines the reactor generated. 5 days after starting the new GFO reactor the following has happened with no other changes:

PO4 went from 0.16ppm to 0.34ppm. It went up.
PH went from 8.3 to 8.45, highest it's ever read.
Alk went from 8.5 to 7.3 (I am correcting this slowly)

My leather corals have never looked so good, but a couple of my favorite SPS pieces are losing flesh. See picture.




I have shut down the reactor until I can sort this out. Any ideas, am I experiencing what I have read about GFO harming SPS corals?

 

[Stlrockguy]

Wow that's no good. Maybe I'll stick with phosgaurd most of my coral are SPS, LPS.

 

[Sniperhank]

The only negative ice ever been aware of with gfo is adding too much and bringing the phosphates down too quickly and shocking corals, such as sps. If the levels of phosphate went up or down quickly, this could be the same effect you are seeing out of the more sensitive coral.

 

[Gregcoyote]

Why would the PO4 climb over 4 days? I think the reactor was generating GFO fines that were escaping into the system. But all I can read says the damage to SPS was I used too much and crashed PO4 levels, which didn't happen. So far I am thinking Phosgard was safer in the long run. I am sure hoping these corals recover, took years to grow them.

 

[mr_X]

I just think that any sudden changes are bad for sps. I have no idea why your parameters did what they did though. I have always read that you need to start very slowly with GFO, and work up to the recommended amount for your system, not add it all at once (or twice as much even).

 

[Gregcoyote]

Yes, I screwed up on that one. My "theory" was what's the harm of creating a large PO4 filter when I was already at 0.16ppm? I was only shooting to drop to 0.05ppm. Not much of a change. Instead it climbed the other direction to 0.35ppm and Alk fell. My guess it's the sudden alk change brought about by 1.5L of GFO added at once to a 500 gallon system. On top of that the new reactor seems very efficient.

 

[Gregcoyote]

I removed the GFO, only 5 days old. The high quality stuff. I had rinsed it before being added to the reactor, but when I poured it into a bucket, very dark brown water came off of it indicating it was grinding in the reactor. That's no good. Not sure the cotton filter sock would have caught this material. Phosgard beads are at least covered in a plastic coating to keep it from grinding and creating dust. Going to do nothing but a few water exchanges for now and hope these raw spots on my two SPS corals recedes.

 

[Dary421]

You got my attention on this topic,..rather interesting,...,will you be running phosguard or something else in it's place immediately or just let thing settle in for awhile without using anything?

 

[Gregcoyote]

Letting it settle out first. As Doug said, too abrupt a change is disaster. I am very slowly bringing alk back up to 8 or 9dkh.

 

[00youknowit00]

I was under the impression that you did not want gfo to tumble all, as its so soft it just breaks itself apart..

 

[huma-huma]

I believe you have GFO confused with carbon

 

[00youknowit00]

Well I never tumble either, may just be me. Just barely enough flow to keep it fluidized. Since the fines from them grinding are not good at all. Even on BRS it says not to tumble it hard if I remember correctly..

 

[Gregcoyote]

It's a crazy balance of too much tumbling and grinding it up, or to little and it sets up in a brick. But in retrospect, there are more downsides to GFO than I first knew. The alk and calcium depression is bad enough, but this finicky stuff is hard in a high calcium tank to work with.

It's back to phosguard. You can see when it's exhausted, it doesn't grind itself up, at least if I keep the tumbling down to a slow level. It doesn't gel out. And it doesn't mess with alk and cal. Will start out much slower though and about half the recommended amount for the first few days.

Average cost of high capacity GFO, 1.7L is $18-25
Average cost of phosguard, 2L is $25-29
So the difference isn't bad. But I hear the phosguard doesn't last as long.