Experiences with GFO, Helpful or Harmful

So it seems that lately I have been reading a lot of threads where many of our overall reefs have been suffering for some unknown reason with spot on parameters. It is often suggested that the GFO be taken offline as it may be the likely culprit even though it has been such a staple in our hobby for many years. I am not sure if it is due to technology advancing so far that running GFO is keeping our systems to clean from organics, absorbing beneficial micronutrients, or leaching things such as iron into the water column. A lot of literature if out there on the topic to cover this so I am not going to even attempt to sum it all up but want to create a thread to share our experiences with GFO to help out fellow reefers attempting to maintain a perfect reef setup.


Ill start with my experience. I had my 46 gallon setup for about 9 months and added various livestock including my CUC, fish, and many corals. I keep mostly softies and lps but have a few leathers, mushrooms, and sps as well. I had great luck with almost all corals except for some acan frags and an ORA red planet that just didnt seem to be doing well. I also had the green film algae grow on the glass that needed cleaned every 4-5 days but had no cyano or hair algae. I did not run a skimmer, GFO, sump, or fuge but a HOB filter with carbon and phosguard by Seachem. i performed a 5gal WC weekly and occasionly would increase it to 10gal if I saw any rise in nitrates during the first 6 months.
It was after these 9 months I decided to try GFO since a lot of literature states chemicals such as phosguard can leech aluminum into the water and cause harm to corals. I also wanted to decrease the frequency in which I would need to clean my glass and was also hoping that adding GFO would help my Red Planet do better. I ordered BRS GFO and added the suggested dose to my HOB filter. IMMEDIATLY my zoas closed up and my leather shriveled. I did rinse VERY well and even put some fine filter pad right in front of the GFO to prevent any small particles getting into my reef. I did read that iron content does rise with GFO but it is usually in the form of insoluable particles that does nto effect tank inhabitants. After a few days I had no improvement in my zoas or leather and decided to cut the dose in half. It still took abotu a week for my leather to start to open for a few hours every day but it wasnt until a good month or so did it appear to open normally again. My zoas took even longer but never did open as nice as they had before and after a couple months many of my lps did not seem to open quite as nicely as before. I also developed cyano outbreaks even though my nitrates were 0 and my phosphates 0-0.02. The tank just overall just seemed to lose that perfect balance sparkle it had previously and I was not happy with how my corals looks at all. I also had to start doing a LOT of ALK and CA and had a very hard time getting my ALK to stay above 8.
I decided it is time to end the GFO experiment. I took it offline about 5 days ago and did a 5 gal WC. My Alk is actually climbing again to the point I have to keep checking and dialing back my dosing pump. My CA also rose to clsoe to 500 where I turned the dosing pump off for 3 days and restarted it at a lower rate as well. The cyano growth seems to be slowing, we will see how t hat goes. The corals dont look all that different yet but I believe that to be due to the ALK and CA swings as I try to get things dialed in again with the dosers. I am going to restart my phosguard in the next couple weeks and do a larger WC this weekend to try and remove whatever may be in the water from the GFO. It is still too soon to say if GFO was the culprit, but I believe it very well may be in my case. Ill keep you guys informed on how the tank responds in the upcoming weeks.

 

My DT's params are very good lately,

But what I really took out of your well written scenario, is that you were concerned when you had the clean the glass every 4-5 days?

I can rarely let mine go 3 days, but figured it was just par fort the course ( I never really even play golf)!

 

I believe one issue we are having is that we are putting GFO on very young systems that are low in phosphates and nutrients already. Phosphates tend to bind to liverock and sand therefore building up over time. When our systems are young, phosphates are at a low enough level, we really don't need to use GFO. As a matter of fact, I believe corals benefit somewhat from a little phosphate in the water anyway. That's just my take on it. I was one of those that feel their tank took a downward turn with the addition of GFO. It will be a very very long time before I run it again.

 

I just checked out the link to your thread!

Everything you recently pictured looks fantastic!

 

And its a moderately powerfull skimmer, and a huge chaeto basket in the sump that keeps my DT and inhabitants happy!

 

Good point with that. I didnt test for phosphates at all prior to GFO but did use BRS Pukani which has had some issues with leeching phosphates. I figured since I dont use a skimmer or sump of any kind GFO would be the least I could do to help with SPS health. It might be a staple on very old systems to prevent old tank syndrome verses nuisance on newer cleaner systems.
Did you find your tank to improve after you took it offline?
How long before you saw improvement?

 

The every 4-5 days was generous. It could use it after 2 or 3 but wasnt that bad. By 4 or 5 days it was enough to see from a distance and NEEDED done. Funny thing is since starting the GFO, I had to clean the glass from film algae MORE often. Like mentioned too I NEVER had any cyano issues before either. Only a small spot here and there on occasion I would siphone off and be done with for months. Once starting the GFO though my sand looks like crap within 24 hours of cleaning!! I already see a decrease in the growth of the cyano but its still there using up whats left of the iron I would assume.

You think my tank looks good in those pictures!! Yea the xenia and jasmine polyp explode in growth no matter what I do and the large wall frogspawn front and center is one of my oldest corals that seems to always expand wonderfully. But if you look at the FTS from jan vs april you will see the difference in the green frogspawn front and center. The purple hammer and multicolored on the backleft also dont open up as large as they used too. Lastly the zoas, while they do open again, dont seem to open fully either. Its not that things are suffering and dieing, but since the GFO I havnt had those days where you look at the tank and go WOW, today everything looks amazing!!!

 

Specifically how much GFO did you use and what size is your system? What was the flow rate through the GFO and did you notice it degrading or abrading itself over time?

A common mistake I often see is way too much GFO, especially in the beginning. For some unknown reason BRS recommends at least twice as much media as all other vendors and it can and will lead to the problems you describe. I have always followed the directions TLF uses, maximum dose of 10 grams per 10 gallons or about one level tablespoon full and start with 1/2 dose in the beginning. I choose to keep 1/2 dose in my systems at all times, never going to the full dose and have not experienced any problems in the 9 or so years I have used it. My flow is fed by a MJ400 or MJ600 powerhead feeding two Phosban reactors via a tee and each reactor is valved individually, one with GFO and the other carbon.

 

i too just took my gfo offline to see how things work out. i agree with daniel in that newer tanks probably dont really need it especially if you have a good skimmer, macro algae and a low bio load as with my tank. the phosphates just have not leeched in yet. however i do think that people start off with too much gfo in the beginning. the first dose should be much lower then you will probably need. having too much in the beginning can shock the system by removing too much at once. aka going from a more nutrient rich environment to little phosphate at all. and as we all know drastic changes are never good for reefs. i am excited to see if my corals start to color up some more and maybe speed up growth now that my gfo is taking a break. this is a great topic to talk about!

 

+100 Adding to much, adding it to quick (starting w/ full dose) and/or tumbling it to fast = bad!