GFO stipping rocks

[Marchillo]

I started running High Capacity GFO about 3 months ago - I had cyano, gha, bubble, and algae growing in the sand - looked almost like grass. I am running the recommended amount by BRS. I did not do a ramp up. Since then I've added a diamond goby which did a number on the sand bed and so i don't see signs of the "grass" Maybe buried and died due to lack of light. The cyano is gone. There is still some GHA but that is just because i need to manually remove. The shorter stuff is gone and new stuff isn't growing. I've added a few fish as well so my bioload is pretty high and I am feeding a lot - although they are eating a lot. I only have two small coral frags and they don't seem to be impacted much.

The rocks on the left side of the tank are losing their nice purple color (came from the LFS). I also have a big cuc and a starry blenny that does a lot of grazing. Should i just give the GFO a break for a while and see what happens? Reduce the dosage to half? Everything is fine in the tank. I do not dose anything. I have to do a test soon - haven't done that in a wile and I don't test phosphates - so I'm just changing gfo on a monthly schedule not due to test results.

So is the GFO causing the rocks to be striped of colors? I am getting a healthy amount of coraline on my glass and on other rocks that didn't have it previously.

Thanks for any thoughts.

 

[Xxero]

Does your cuc include any Urchins or Emerald Crabs? Coralline is like Fruity Pebbles to them! :bigeyes:

 

[Sapelo]

Like any other additive to our tanks, GFO should be run incorporated with a good water testing program. Without numbers, how can you know your tank parameters and what impact the GFO is or is not having?
Start testing. That's the way to know if you're overdoing your GFO use.
Sure, you can run too much GFO, can make your tank "too clean," but the way to know that is with numbers not with guessing.

 

[TangingOut]

How about posting a picture of these rocks. Are they man made purple rocks? If so, they won't stay that color as they mature and get covered in all sorts of stuff.

 

[DrewHaus]

GFO is pretty potent stuff. Like others said, it's best to use it with a (phosphate) test kit, otherwise you have no idea how it is changing your water chemistry. Testing is particularly important for determining when GFO gets exhausted and ready to change.

 

[Marchillo]

Everyone makes great points. So here are my thoughts. I also left out some important info

- when I first added the gfo the rock seemed to lose a bit of color
- I tried the Hanna phosphate checker way back and had trouble. Perhaps I'll give it a try
- I do have an urchin and he's been on those rocks lately
- I also have a radion out - waiting for a part from ecotech and its that side of the tank

So my thinking was add the gfo and run it for a month. If it was exhausted after a day then so be it. I was gonna see if the algae issue got better after a few months. Gfo is expensive. Unless my issue kept getting worse I wasn't changing it daily or weekly etc.

So I figure after a month it would be exhausted so I'd let the look of the tank tell me how it's doing. And it's telling me it's stripping the rocks. The urchin and radion are probably factors but that stuff is after I saw the gfo initially stripping the rocks.

 

[anthonys51]

i dont think the GFO is stripping your rock clean. gfo takes phosphate out of the water, Coraline algae doesn't need high phosphates to live. my tank has immeasurable phosphates and a ton of coraline. you need to test your waters. if you plan on running a reef tank these are the test you need
alk test kit
calcium test kit
magnesium test kit
phosphate test kit
ph test kit
nitrate test kit
stop guessing whats wrong with your tank and find out whats wrong

 

[Marchillo]

I do test. Just not phosphate. I'll try the Hanna again. I have all those other tests and test pretty regularly.

I am about to start "reefing" been doing great with the fish. I was having issues with the Hanna checker. It's not that I don't want to test but it seemed futile and unreliable.

Any test kits people can recommend for phosphates?

 

[VWD]

You said The rocks on the left side of the tank are losing their nice purple color (came from the LFS). How long has the rock been in the tank, Sometime it will die off after a move.

I also don't think GFO is causing the problem

 

[Marchillo]

Ok that is good to know. Rock has been in for 6 months or so. Like my second post states above there is a bunch of stuff happening on the left side of the tank. My urchin is moving around a lot since the light has been off about a week waiting for the part from ecotech. But about 2.5 months ago I initially thought the rock lost a bunch of color after gfo. But I did add a bunch of bumble bee snails and a few turbos so with the feedback here it seems the timing of the gfo is coincidental.

I thought that people who run gfo, run it all the time. If it typically exhausts after a month I really didn't see any harm running it for a month at the recommended dosage and changing it monthly. If it was exhausting quickly then no good or harm would be happening by letting it continue to run. But I'll try the Hanna again.

So no light and the urchin are probably doing a number on coralline and other algae.