When to change GFO?

[Pigpen17]

So I have a GFO question. I have been running GFO for a few weeks, and it has started to make a dent in my GHA forest. Now I have read everything on here from changing it out every month, or every three months, and today I heard advice to change it out every three days or so. I need to buy a test kit, but even then, as I understand it, the test will come out much lower than it actually is because the algae is using it up. I guess there is no harm in changing it every three days, except cost, but what would you all do?

 

[kgeig001]

I change mine out one a month. If you want to really get precise just test the affluent that exits the reactor. It should read 0 if it's doing its job. Changing GFO every three days or so is usually when you have a bad phosphate problem and you're trying to bring it down. Once it comes down and you have determined the phosphate is under control and stable...usually replacing it once a month is pretty much the norm...I think

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[Pigpen17]

I change mine out one a month. If you want to really get precise just test the affluent that exits the reactor. It should read 0 if it's doing its job. Changing GFO every three days or so is usually when you have a bad phosphate problem and you're trying to bring it down. Once it comes down and you have determined the phosphate is under control and stable...usually replacing it once a month is pretty much the norm...I think

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Good to know. Thanks. I'm getting my test kit in the mail. Then I guess I'll know more. As of now, I think once a month is my plan.

 

[Greybeard]

Yup, Kgeig001 has it. Run water from your GFO reactor to a small vessel, and test that.

New reactor, trying to 'fix' a problem that already exists, I'd probably change it more often. Settled, stable tank? Once a month is fine. Even longer, if you don't see any changes. I'm starting to change every 2 months. If I readings don't go above 0.06 in two months, I may extend it even further.

I recommend a low range Hanna checker. Highly recommend. Nothing else seems to work.

 

[Pigpen17]

Wow! The Hanna checker is spendy! I'll have to think about that one.

So let me see if I am hearing you guys right. If I have a bad problem, which I am pretty sure I do, than I should be changing more often. Once I am under control, than once a month is probably fine. Maybe even less.

I am pretty sure my rocks are huge leaches. I have had them a very long time.

I'll go ahead and change it out tonight, wait for my test kit, which won't work very well but it will at least be something. Test my water in the tank and also the water coming out of the reactor to see where I'm at. Probably keep changing every few weeks until I am in better shape.

Thank you all.

 

[thegrun]

GFO is also expensive, you need to test! Usually when there is an algae issue you will need to change out the GFO frequently until the algae is under control. Every three days may be necessary if the problem was bad, but weekly will probably suffice. Once the algae is knocked down, monthly changes are usually enough.

 

[DrPheel]

Wow! The Hanna checker is spendy! I'll have to think about that one.

So let me see if I am hearing you guys right. If I have a bad problem, which I am pretty sure I do, than I should be changing more often. Once I am under control, than once a month is probably fine. Maybe even less.

I am pretty sure my rocks are huge leaches. I have had them a very long time.

I'll go ahead and change it out tonight, wait for my test kit, which won't work very well but it will at least be something. Test my water in the tank and also the water coming out of the reactor to see where I'm at. Probably keep changing every few weeks until I am in better shape.

Thank you all.

The algae will bind the phosphates quickly so you may not see anything on your test kit (even hanna). If you have GHA in the tank , well you have Phosphate.. don't need a test kit or a PHD in chemistry from what I have learned from my GHA outbreak, the best is to pull and syphon everything out when doing a good water change. Make sure you use RO/DI water or you are pretty much causing the issue and working against your GFO. If you have affected rocks you can remove , put them in your old water change bucket and scrub them off good with a big brush. Some ppl also use peroxide dip on affected rocks to kill of the algae but I was able to manage my outbreak with no chemicals so I am confident it can be done without. Once that's done change your GFO and start monitoring the effluent of the reactor. It will give you a much better reading since you will have gotten rid of all your phosphate the algae leached and it will not bind it before it recovers. Keep on top of your water changes and with time , you will see the algae will be weaker and easier to pull from the rock its on. This is a good indication that your phosphate are on the low and the algae will have trouble surviving. You can then keep a tab of your effluent water from the reactor to gauge when to change it.

Happy Reefing :beachbum:

 

[Pigpen17]

Great post. Thank you. I clean as much as I can out every weekend when I do my water change. I will keep at the GFO and heed your advice. The tip that a few of you mentioned to test the water out of the reactor is something I would have never thought of. That's why I love this place.

 

[whosurcaddie]

I always read zero even with low range hanna checker. I change mine out when I have to clean my glass two days in a row. I know at that point the GFO is exhausted. GFO can literally be used up in a day so I would look at the glass for an indication. If you have to clean the glass everyday keep changing your GFO until your glass stays clean for a longer period.

The cheapest GFO on the web: http://www.amazon.com/GFO-Phosphate..._1?ie=UTF8&qid=1462855216&sr=8-1&keywords=GFO

 

[Pigpen17]

Nice. Thank you.

 

[Ebone]

If I have to clean glass more than 2 times a week I change out GFO

 

[Pigpen17]

Actually, the glass is good. I have to do very little cleaning. Maybe once a month a have a little bit to handle. It's the algae on my rocks that are a mess and a hassle.

 

[gallegos]

I change gfo when I get a reading of phosphate. If I'm still testing 0 then I don't change it.

 

[Pigpen17]

Yeah. I haven't changed it yet, and I may not. All the in input I have had in this tread regarding my glass and such, and the fact that I awoke to a few huge pieces of algae free floating in the tank makes me think it's not time yet. I'll wait on my test kit. Thank you.