Who has tried regenerating GFO and quit?

[ostrow]

Trying to figure out if the hassle (it isn't as straightforward as regenerating, say, Purigen), is worth it. What I can't get clear from all my reading is:

1. Does it work with the regular, bulk GFO I get from places like Premium?

2. Exactly how much rinsing is required and, really, how to effect it? I think the only viable way is to fill a large Brute with RO and plumb to a chamber with the GFO that outputs to a drain. Valve that when running lye or muriatic so that it will just recycle through the GFO and effectively soak/regenerate.

So, the brute would have, in sequence, muriatic then lye then RO.

3. The assumption here (seems duh obvious but making sure) that tap water for any stage is a no-no. Right?

So... hassle. Still worth it? As in, how often does the GFO disintegrate to mush (does for some, clearly) and how hard is it to get it in fact regenerated (seems very hard for some).

TIA .... looking forward to the war stories.

[ostrow]

nobody?

[billdogg]

I've never tried it, but with my 3rd large system soon to be up and running, I'd be interested to know the answer too. If I can save a few bucks there, it'll mean a few extra $$$ elsewhere.

tagging along......

[d0ughb0y]

I've tried it and quit. Figured it was not worth the trouble. I'm not really sure how effective it is. Besides, lye is a controlled chemical and not easy to get (at least when I tried , maybe 4 or 5 years ago), and when I sold my leftover lye on craigslist, the buyer looked shady.
I have not used any gfo, carbon etc at all for the last 4 years.

[FullBoreReefer]

Same with me, I recharged for about a year than called it quits. Same thing, just another thing you gotta do, another chemical you gotta buy, another bucket laying around, etc etc...

I use an ATS now...

[outy]

I did a gallon. Pain and gave up on GFO completely after that.


An ATS does close to the same without an added monthly bill factored in.

[jduck]

Gave up and just used lanthanum cloride now

[ostrow]

Hmmm. Well I certainly don't want to risk dosing lanthanum in my tank (not criticizing at all jduck... just difference in approach/preference here).

And not too interested in ATS eihter.

Interesting that all who gave up on regenerating also gave up on GFO. Didn't see that coming.

[dkeller_nc]

I regenerate my GFO regularly. I have a background in chemistry (chemical engineering, to be exact), so handling the sodium hydroxide and dilute hydrochloric doesn't bother me, though it might be a barrier for some.

However, there was an incredibly unfortunate seminal article detailing GFO regeneration in Advanced Aquarist that's downright dangerous and also unnecessary. I honestly wish they'd remove it from the site, someone could get badly hurt following the article if they have a mishap with a hose fitting.

Specifically, the article advised packing GFO into a reactor and using a powerhead to recirculate 1N NaOH solution through the reactor for a number of hours. One should never pressurize a solution like this outside of an industrial setting. 1N NaOH will burn your skin or eyes pretty much instantly, and while it doesn't "fume" like concentrated mineral acids, an aerosol of NaOH can do severe damage to your sinuses and lungs.

And there's absolutely no reason to recirculate the sodium hydroxide solution through the GFO under pressure from the chemistry perspective. The slow step for desorbing the phosphate from the GFO is diffusion through the pores of the solid; fast recirculation of the bulk liquid does nothing to speed this up.

Instead, a reasonably safe way to regen GFO is straightforward and remarkably simple. I say "reasonably safe" as long as you follow the basic precaution of wearing black janitorial gloves and eye protection. Simply place your GFO in a suitable container (I'm usually doing relatively small amounts, so I use 1-1/2 quart glass mason jars) and rinse it several times with tap water until the water runs clear to remove any accumulated detritus. Then prepare a 0.1N HCl solution by diluting concentrated hydrochloric acid (sold as "muriatic acid" in home stores or pool supply houses) 100 to 1 in water. You can use tap water for this step, as the acid will ensure that any contaminants remain in the liquid. Let it soak for an hour or so at room temperature.

Follow the acid soak with 2 rinses of RODI. You don't need to be fastidious about this rinse, it's mainly to prevent a violent reaction with the next step if you messed up the HCl dilution and have more concentrated acid than you thought.

Drain the GFO, and add enough 1N NaOH solution to cover the GFO with about an inch of clear liquid above it. You can make the 1N NaOH solution by dissolving 40 grams of lye (available as "pure lye" from hardware and home stores) in a liter of RODI water. Approximately speaking, that's about 2 tablespoons per quart of water. Let this stand for a day. The following day, pour off the NaOH, and cover the GFO with fresh 1N NaOH. Repeat this one more time.

After the 3rd NaOH treatment, rinse the GFO very thoroughly with RODI. This can take a while; you can speed it up a bit by using 0.1N HCl to rinse the GFO after the first RODI rinse. Don't use 0.1N HCl for the first rinse right after pouring off the 1N NaOH or you risk a violent neutralization reaction that makes a big mess.

That's it - either store the regenned GFO wet in a sealed container, or for long term storage, dry it in a glass baking dish in the oven at 250 F.

[Mr. Brooks]

Glad you explained it. I always felt bad throwing GFO away knowing it could be regenerated. Now I don't feel bad about it anymore.

[dkeller_nc]

That's a personal choice, of course. In my case, it's just a couple of 1-1/2 quart mason jars setting on the counter for 3 or 4 days; one that holds the lye solution, and the other that holds the GFO being regenerated. And $80 for 1/2 gallon of the stuff, and considering that it can be regenerated 10 or more times, it's worth it to me.

But if you don't use GFO continuously, I can see how it'd be easier to just toss it.

[sfdan]

Originally Posted by Mr. Brooks

Glad you explained it. I always felt bad throwing GFO away knowing it could be regenerated. Now I don't feel bad about it anymore.

haha

[gobble]

Originally Posted by dkeller_nc

I regenerate my GFO regularly. I have a background in chemistry (chemical engineering, to be exact), so handling the sodium hydroxide and dilute hydrochloric doesn't bother me, though it might be a barrier for some.

However, there was an incredibly unfortunate seminal article detailing GFO regeneration in Advanced Aquarist that's downright dangerous and also unnecessary. I honestly wish they'd remove it from the site, someone could get badly hurt following the article if they have a mishap with a hose fitting.

Specifically, the article advised packing GFO into a reactor and using a powerhead to recirculate 1N NaOH solution through the reactor for a number of hours. One should never pressurize a solution like this outside of an industrial setting. 1N NaOH will burn your skin or eyes pretty much instantly, and while it doesn't "fume" like concentrated mineral acids, an aerosol of NaOH can do severe damage to your sinuses and lungs.

And there's absolutely no reason to recirculate the sodium hydroxide solution through the GFO under pressure from the chemistry perspective. The slow step for desorbing the phosphate from the GFO is diffusion through the pores of the solid; fast recirculation of the bulk liquid does nothing to speed this up.

Instead, a reasonably safe way to regen GFO is straightforward and remarkably simple. I say "reasonably safe" as long as you follow the basic precaution of wearing black janitorial gloves and eye protection. Simply place your GFO in a suitable container (I'm usually doing relatively small amounts, so I use 1-1/2 quart glass mason jars) and rinse it several times with tap water until the water runs clear to remove any accumulated detritus. Then prepare a 0.1N HCl solution by diluting concentrated hydrochloric acid (sold as "muriatic acid" in home stores or pool supply houses) 100 to 1 in water. You can use tap water for this step, as the acid will ensure that any contaminants remain in the liquid. Let it soak for an hour or so at room temperature.

Follow the acid soak with 2 rinses of RODI. You don't need to be fastidious about this rinse, it's mainly to prevent a violent reaction with the next step if you messed up the HCl dilution and have more concentrated acid than you thought.

Drain the GFO, and add enough 1N NaOH solution to cover the GFO with about an inch of clear liquid above it. You can make the 1N NaOH solution by dissolving 40 grams of lye (available as "pure lye" from hardware and home stores) in a liter of RODI water. Approximately speaking, that's about 2 tablespoons per quart of water. Let this stand for a day. The following day, pour off the NaOH, and cover the GFO with fresh 1N NaOH. Repeat this one more time.

After the 3rd NaOH treatment, rinse the GFO very thoroughly with RODI. This can take a while; you can speed it up a bit by using 0.1N HCl to rinse the GFO after the first RODI rinse. Don't use 0.1N HCl for the first rinse right after pouring off the 1N NaOH or you risk a violent neutralization reaction that makes a big mess.

That's it - either store the regenned GFO wet in a sealed container, or for long term storage, dry it in a glass baking dish in the oven at 250 F.

Is there a risk with this that some of the chemicals will be left in/on the GFO and be released into the tank when put back in the reactor?

[ostrow]

DK my questions as well.

First, the article and the thread mention people rinsing 15-20x with RO after the lye treatment. And inside a reactor with powerhead. However, over the years I have learned to trust you on stuff like this.

Just want to make sure you meant what you said -- a couple RO rinses, maybe one with weak HCL -- using powerhead and reactor, or just in the mason jar?

[FullBoreReefer]

If anyone needs lye I have plenty and no longer use it. PM me...

[d0ughb0y]

Originally Posted by ostrow

Hmmm. Well I certainly don't want to risk dosing lanthanum in my tank (not criticizing at all jduck... just difference in approach/preference here).

And not too interested in ATS eihter.

Interesting that all who gave up on regenerating also gave up on GFO. Didn't see that coming.

I found it better to spend the effort to reduce/eliminate the source of PO4 rather than fixing the symptom. That may not applicable to everyone though. For me, its bare bottom and reduced the number of fish. Never needed GFO since.

As to source of lye, unless things changed since 5 years ago, I was not able to find any source of pure lye in any local retail store. Since it is a controlled chemical, once you start purchasing regularly online, don't be surprised if you are always selected in airport "random" searches.

[ostrow]

The gfo sits at the bottom of the jar. Any need to agitate it?

Originally Posted by dkeller_nc

I regenerate my GFO regularly. I have a background in chemistry (chemical engineering, to be exact), so handling the sodium hydroxide and dilute hydrochloric doesn't bother me, though it might be a barrier for some.

However, there was an incredibly unfortunate seminal article detailing GFO regeneration in Advanced Aquarist that's downright dangerous and also unnecessary. I honestly wish they'd remove it from the site, someone could get badly hurt following the article if they have a mishap with a hose fitting.

Specifically, the article advised packing GFO into a reactor and using a powerhead to recirculate 1N NaOH solution through the reactor for a number of hours. One should never pressurize a solution like this outside of an industrial setting. 1N NaOH will burn your skin or eyes pretty much instantly, and while it doesn't "fume" like concentrated mineral acids, an aerosol of NaOH can do severe damage to your sinuses and lungs.

And there's absolutely no reason to recirculate the sodium hydroxide solution through the GFO under pressure from the chemistry perspective. The slow step for desorbing the phosphate from the GFO is diffusion through the pores of the solid; fast recirculation of the bulk liquid does nothing to speed this up.

Instead, a reasonably safe way to regen GFO is straightforward and remarkably simple. I say "reasonably safe" as long as you follow the basic precaution of wearing black janitorial gloves and eye protection. Simply place your GFO in a suitable container (I'm usually doing relatively small amounts, so I use 1-1/2 quart glass mason jars) and rinse it several times with tap water until the water runs clear to remove any accumulated detritus. Then prepare a 0.1N HCl solution by diluting concentrated hydrochloric acid (sold as "muriatic acid" in home stores or pool supply houses) 100 to 1 in water. You can use tap water for this step, as the acid will ensure that any contaminants remain in the liquid. Let it soak for an hour or so at room temperature.

Follow the acid soak with 2 rinses of RODI. You don't need to be fastidious about this rinse, it's mainly to prevent a violent reaction with the next step if you messed up the HCl dilution and have more concentrated acid than you thought.

Drain the GFO, and add enough 1N NaOH solution to cover the GFO with about an inch of clear liquid above it. You can make the 1N NaOH solution by dissolving 40 grams of lye (available as "pure lye" from hardware and home stores) in a liter of RODI water. Approximately speaking, that's about 2 tablespoons per quart of water. Let this stand for a day. The following day, pour off the NaOH, and cover the GFO with fresh 1N NaOH. Repeat this one more time.

After the 3rd NaOH treatment, rinse the GFO very thoroughly with RODI. This can take a while; you can speed it up a bit by using 0.1N HCl to rinse the GFO after the first RODI rinse. Don't use 0.1N HCl for the first rinse right after pouring off the 1N NaOH or you risk a violent neutralization reaction that makes a big mess.

That's it - either store the regenned GFO wet in a sealed container, or for long term storage, dry it in a glass baking dish in the oven at 250 F.

[ostrow]

Well, it turned to mush. And, if anything, I went light on the muriatic and lye concentrations.

Seems like this won't work so well...

[dkeller_nc]

Sorry, I didn't see this thread again after I posted to it a while back.

With respect to the GFO "holding together", it's going to vary depending on the porosity of the particular GFO brand. BRS high capacity GFO works very well - it consists of relatively small, hard particles that don't degrade in the initial 0.1 N HCl treatment. There are some GFOs, however, that are highly porous, relatively soft particles where acid could potentially break down the internal structure of the particle. On the other hand, the sodium hydroxide solution shouldn't do any damage to the particle structure.

With respect to the rinsing step, the key thing to remember is that what would potentially be left in the GFO from incomplete rinsing is sodium hydroxide. Getting this into the tank would do nothing other than increasing the alkalinity. Since one is typically using a fairly small amount of GFO compared the the tank volume and at least 2 to 3 rinses will bring the initial concentration of the sodium hydroxide solution down at least 90% or so, there's little worry about substantially altering the alkalinity of your tank water.

Also, if you regenerate in a Mason jar, you don't need to stir the GFO so long as you let it set for at least 12 hours in each rinse.

Again - never do this is a reactor. It's dangerous.

[ostrow]

Originally Posted by dkeller_nc

Sorry, I didn't see this thread again after I posted to it a while back.

With respect to the GFO "holding together", it's going to vary depending on the porosity of the particular GFO brand. BRS high capacity GFO works very well - it consists of relatively small, hard particles that don't degrade in the initial 0.1 N HCl treatment. There are some GFOs, however, that are highly porous, relatively soft particles where acid could potentially break down the internal structure of the particle. On the other hand, the sodium hydroxide solution shouldn't do any damage to the particle structure.

With respect to the rinsing step, the key thing to remember is that what would potentially be left in the GFO from incomplete rinsing is sodium hydroxide. Getting this into the tank would do nothing other than increasing the alkalinity. Since one is typically using a fairly small amount of GFO compared the the tank volume and at least 2 to 3 rinses will bring the initial concentration of the sodium hydroxide solution down at least 90% or so, there's little worry about substantially altering the alkalinity of your tank water.

Also, if you regenerate in a Mason jar, you don't need to stir the GFO so long as you let it set for at least 12 hours in each rinse.

Again - never do this is a reactor. It's dangerous.

Ahh. Ok will try next time without the muriatic step.