Why am I so Bad with GFO

crabgrass · Feb 4, 2024

I have a fundementual misunderstanding of how to use this stuff. New tank. Using Hanna LR (not ULR)

Last month, my phosphates jumped to 0.3. Based on some forum feedback, I put in a half dose of Phosguard into my tank (yes, I was measuring actual water volume and not display + sump total volume). Within 2 days Hanna was reading 0.0.

Over the last month month, my phosphates slowly crept up to 0.14 (0.01 - 0.03 a week). On my own stupid advice, I put in a very small dose of Rowaphos (like an 1/10 of recommended). Within 16 hours, phosphate levels were nuked again.

My assumption are:
1) First instance was from phosphates leaching from rocks (newer dry rocks, new tank). The actual natural degrading of food/waste was much less and it just absorbed everything

2) second case - similar. My output of phosphates exceeds usage (by fuge, corals, etc, etc) by 0.01 -0.02 a week. Whatever amount of GFO I put in just soaked up everything. I am assuming if I put in like a 1/50 or something rediculous it could have dropped it down without nuking it. Like a couple of granuals based on how much Rowa I put in this time

I know since I am not using ULr it might not be completly nuked. However, I clearly didnt understand how immediate and severe the drop would be.

Are there smarter ways to manage this? Maybe just run my fuge longer (already 12 hours a day).

**edit
1) I run a slightly oversized skimmer 24x7, and collect enough to dump out 2-3 a week

2) Tank has 85 lbs dry rocks that are 60 days old (did a 100% WC for them initially when transferring to display). Also 15 lbs of ocean live rock

musel101 · Feb 4, 2024

Makes two of us lol I’m bad to

crazyfishmom · Feb 4, 2024

What size tank? Carbon dosing might be enough to help you deal with your phosphates since it seems like you just need to balance out consumption. Justa. Thought.

musel101 · Feb 4, 2024

crazyfishmom said:
What size tank? Carbon dosing might be enough to help you deal with your phosphates since it seems like you just need to balance out consumption. Justa. Thought.

I’m doing okay it’s only one of my tanks is doing okay my experiment tank sugar works in small doses for me

crabgrass · Feb 4, 2024

crazyfishmom said:
What size tank? Carbon dosing might be enough to help you deal with your phosphates since it seems like you just need to balance out consumption. Justa. Thought.

85 total water volume (measured). 100g display + 50g sump.

Yes, I thought about carbon as well. My nitrates aren’t incredibly high (11). My under standing is that carbon dosing will drop N faster than P. I think if I effectively wanted to use it to drop P, I would need to dose N and use carbon simultaneously ? Seems counter productive-ish.

musel101 · Feb 4, 2024

crabgrass said:
85 total water volume (measured). 100g display + 50g sump.

Yes, I thought about carbon as well. My nitrates aren’t incredibly high (11). My under standing is that carbon dosing will drop N faster than P. I think if I effectively wanted to use it to drop P, I would need to dose N and use carbon simultaneously ?

From my understanding carbon dose will affect both at the same time p and n. But honestly not sure if you need to increase n

musel101 · Feb 4, 2024

How your ceramic media and rock work do you think you have enough?

crazyfishmom · Feb 4, 2024

crabgrass said:
85 total water volume (measured). 100g display + 50g sump.

Yes, I thought about carbon as well. My nitrates aren’t incredibly high (11). My under standing is that carbon dosing will drop N faster than P. I think if I effectively wanted to use it to drop P, I would need to dose N and use carbon simultaneously ? Seems counter productive-ish.

It will drop both but once you establish a balanced ratio the system stabilizes and dosing nitrate becomes less necessary. Most corals love stability and the huge swings in phosphate can start to have deleterious effects and lead to tank crashes. Carbon dosing works much more gradually. It also allows you to control your system using bacteria which in turn feeds your coral and balances your ecosystem. Obviously I am a big proponent of it or I would not suggest it. Depends on what type of corals you keep and how stable you need your system to be. GFO can always be problematic even in mature systems because if consumption changes at all you can find yourself in a touch spot.

Mikeltee · Feb 4, 2024

Your rocks are Phosphate bound. It takes about 6 months to fix. Only growing Algae will export it. You using all of these chemicals is very detrimental to the process. I really hope that you don't have any livestock in there. Immediately stop what you are doing! Let it sit for 2 weeks and take a measurment at that point to reassess. Turn your lights on so that you have 400 par at the top. You can speed up the process with an Algae Turf Scrubber. It will also help with the hair Algae on the rocks.

My rocks are Phosphate bound. They started at 1.5ppm. It is now 3 months in and at .3ppm. I have a upflow Algae Scrubber and no hair Algae on the rocks. I don't even need to scrape the glass since I got it online.

crabgrass · Feb 4, 2024

Mikeltee said:
Your rocks are Phosphate bound. It takes about 6 months to fix. Only growing Algae will export it. You using all of these chemicals is very detrimental to the process. I really hope that you don't have any livestock in there. Immediately stop what you are doing! Let it sit for 2 weeks and take a measurment at that point to reassess. Turn your lights on so that you have 400 par at the top. You can speed up the process with an Algae Turf Scrubber. It will also help with the hair Algae on the rocks.

My rocks are Phosphate bound. They started at 1.5ppm. It is now 3 months in and at .3ppm. I have a upflow Algae Scrubber and no hair Algae on the rocks. I don't even need to scrape the glass since I got it online.

Yeah, GFO was pulled the second I got the 0.0 reading. I think you recommended in another thread to add it when it got to 0.3

Anyway, it will naturally climb back up as I am feeding pretty heavy right now. My goal is to keep the numbers as stable as possible. I might run Fuge lights longer and look into ATS

Mikeltee · Feb 5, 2024

crabgrass said:
Yeah, GFO was pulled the second I got the 0.0 reading. I think you recommended in another thread to add it when it got to 0.3

Anyway, it will naturally climb back up as I am feeding pretty heavy right now. My goal is to keep the numbers as stable as possible. I might run Fuge lights longer and look into ATS

I would never recommend GFO nor any other phosphate reducing chemical. GFO is dangerous! It is best left to the experts. Companies push GFO because it leads to a lot of problems. Guess who has the solution to the problems???

I lost a 2.5 year battle to dinos because I used GFO. GFO is not going to pull the Phosphate out of your rocks. Only Algae is. GFO pulls the phophate out of the water column. The last thing you want is dinos bro... trust me! Just let nature take its course. Fish don't mind the higher Phosphates. Its best to wait until coralline has covered the rocks anyways to add any coral. Just set aside the cash that you would be spending on corals now for about 6 months. Maybe get an Algae Scrubber to speed things up a bit....

Mikeltee · Feb 5, 2024

I just looked through your posts. I'm not sure that your rocks are Phosphate bound. Where did you get your Marco Rock? I got mine from BRS and it didn't have any Phosphates in it. I doubt your ocean rock had an abundance of Phosphates.

What test kit are you using? What's your water change schedule? What are you dosing? What's your feeding schedule?

If you are using Hanna checkers, and you should be, make sure that you are wiping the glass before putting the sample in the checker. Also align it the same way for both readings. I like to align the 10ml writing in the front on the meter. While the vial may look perfect to you, I assure you that it is not. This is why people complain about the Ca Checker. Its because they don't know how to use it. Two more items to perfect your Nitrate and Phos testing is rinsing the clean vial in tank water before you test as well as making sure that when opening the pouch, you do so in a fashion that does not touch the envelope where you are pouring the chemicals out at. This is tricky. Of course you should also be rinsing your vials out in RODI immediately after testing and letting them dry.

You shouldn't be dosing anything at this point. You can run Kalk if you would like. I started 2 tanks at the same time you did. One has a kalk stirrer and the other one I use 4gram/gal of RODI for topoff because it's a small tank in the basement with no airflow therefor has low pH. I mix 5g at a time and it lasts 10 days. You have a big tank so I'd just go with a kalk stirrer if you want to add something.

DanyL · Feb 5, 2024

Are you sure your phosphates were actually this high?

One key point many miss in measuring nutrients is measuring them “in idle”, meaning not waiting enough time after feeding the tank, cleaning the glass, doing a water change and so on.
All these will skew the test results and would make it seem like they’re more elevated than they really are.

My approach to this is to wait 6 to 8 hours after anything that may influence nutrients in the tank, the upper limit also gives me a comparable decay time between tests.

As for the use of GFO or Lanthanum Chloride - these are the big, heavy guns you pull only when you have large amounts of phosphates bound into your rocks and you aren’t able to deal with it otherwise.

Randy Holmes-Farley · Feb 5, 2024

What are the most recent N and P values when not using GFO or phosguard?

crabgrass · Feb 5, 2024

Randy Holmes-Farley said:
What are the most recent N and P values when not using GFO or phosguard?

11 N, 0.14 P

Randy Holmes-Farley · Feb 5, 2024

crabgrass said:
11 N, 0.14 P

I would not do anything about that, given your reported observations of what happened when you did.

Troylee · Feb 5, 2024

crabgrass said:
11 N, 0.14 P

These are perfect numbers, just let the tank do its thing… I seen your post earlier saying your nitrate is sky high? That’s not high at all I’d even raise them if you could.. 15-20 is a good nitrate reading.

crabgrass · Feb 5, 2024

DanyL said:
Are you sure your phosphates were actually this high?

One key point many miss in measuring nutrients is measuring them “in idle”, meaning not waiting enough time after feeding the tank, cleaning the glass, doing a water change and so on.
All these will skew the test results and would make it seem like they’re more elevated than they really are.

My approach to this is to wait 6 to 8 hours after anything that may influence nutrients in the tank, the upper limit also gives me a comparable decay time between tests.

As for the use of GFO or Lanthanum Chloride - these are the big, heavy guns you pull only when you have large amounts of phosphates bound into your rocks and you aren’t able to deal with it otherwise.

Very good point on this, and I did not consider this.. Tests were pulled maybe 1-3 hours after feeding / cleaning glass, but before WC.

I will try and get a more consistent timing for tests.

crabgrass · Feb 5, 2024

Troylee said:
These are perfect numbers, just let the tank do its thing… I seen your post earlier saying your nitrate is sky high? That’s not high at all I’d even raise them if you could.. 15-20 is a good nitrate reading.

Nitrate was always inline. I would be happy if it stuck there