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Phosphate and GFO

A while back I bought some high capacity GFO from BRS on one of our group buys. I was using it in one of my tanks and didn't really monitor how it was working. I didn't measure the difference before using GFO and after its use. Mostly because I had a regular test kit and hate using them.

Then I bought a Hanna Phosphate checker from AO and it is so easy to use that I started testing all my tanks. My phosphates levels in one of my tanks were high. They were 2.50 + on the Hanna checker. To nights ago I installed a BRS duel reactor with some of the GFO and some carbon. I measured the Phosphates in that tank this morning and the reading was .90. I was really surprised at how quickly the GFO brought down the phosphate level in the tank. I am a believer. I will check again tomorrow.
 

magic

Officer Emeritus
Officer Emeritus
You have to be careful how quickly you bring it down. There are corals that will have a negative reaction if phos goes down to fast. Make sure you put the proper amount in as more isn't better in this case.

Bob
 
You have to be careful how quickly you bring it down. There are corals that will have a negative reaction if phos goes down to fast. Make sure you put the proper amount in as more isn't better in this case.

Bob

And/Or, put it on a timer and only run it part of the day.
 
Thank you for the heads up and suggestions.

I do believe I am running the correct amount. It is a 200 gallon system. I am using about 2 cups of the HC GFO. The BRS website says start out with 1 tbsp per 4 gallons of water. 16 tbsp per cup = 64 gallons. 2 cups = 128 gallons. Although this is HC GFO and you only need half the amount. I may be slightly over dosed. I will check my phosphate level again shortly.
 

mnat

Officer Emeritus
Staff member
Moderator
If you go over to BRS right on the top of their website is a calculator. You can enter in your total water volume and they will give you the exact amount. Works good for someone like me who is not good at math.
 
If you go over to BRS right on the top of their website is a calculator. You can enter in your total water volume and they will give you the exact amount. Works good for someone like me who is not good at math.

It says for 200 gallons use 1.56 cups or 25 tbsp of the HC GFO. I only guessed at how much I poured in the container. After looking at it there seems to be less that 2 cups. I guess I will take it out and measure it exactly. I did another phosphate reading and it dropped another couple points to 0.86 since this morning.

If I can only get my nitrates to drop like this.
 
Checked phosphates today around 3pm and PO4 was down to 0.20. I also ordered some NAOH/Sodium Hydroxide to recharge the spent GFO. Has anyone considered or have recharged their GFO? Seems like an easy and inexpensive thing to do.
 

magic

Officer Emeritus
Officer Emeritus
Checked phosphates today around 3pm and PO4 was down to 0.20. I also ordered some NAOH/Sodium Hydroxide to recharge the spent GFO. Has anyone considered or have recharged their GFO? Seems like an easy and inexpensive thing to do.

Paul (redfishbluefish) does it all the time. At on point members were giving him their spent GFO.

Bob
 
My phosphate reading this morning went up to 0.68. I checked the reading twice. I even did lighter than normal feedings yesterday.

I have no sand bed in this tank or in the fuge. It is not coming from my water source. I maintain the RODI filters well and use multiple tds meters to make sure all is operating as it should.

Something is leaching the phosphates back into the water. Could it be from the algae in the tank dissolving and leaching PO4 back into the system? Or possibly the rock is the source?


I will give another reading tonight or tomorrow.

Steve there is good information on regeneration here.
http://www.reefcentral.com/forums/showthread.php?t=1734717&highlight=gfo+regenerating


 
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Time to change the GFO. Readings today are 0.84 after another day of light feedings. At this rate the only way I can afford to run GFO is to regenerate it. I hope my sodium hydroxide gets here soon.
 
Not yet. Too many projects too little time. I am not sure what system to put it on. I am kind of thinking that the reactor I have is a little on the large size for a first go at it ;).

I want to try it out on a smaller scale first to see if I can get a handle on it.
 
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