Phosphate Issues

[pandaparties]

So about a year ago all my coral got nuked due to some heavy metal contamination and I switched to FOWLR but i wanted to give it another try and I'm trying to get my parameters in coral range but im having PO4 issues. For the past month or so they have been consistently 2.0ppm which is obviously high but my fish have never seemed to care. I have run GFO in the past so i started that for the past week but my phosphates have actually climbed to 2.5 since starting which i thought was weird. I've tried ramping up the amount and every time i do it keeps climbing proportionally. My tank is large total volume wise at like 5/600g but i have about 128oz (one of those big brs tubs) running right now and my numbers have only gone up from where they were always at before. I have some in a reactor tumbling and some in my filter socks.

My nitrates are around 3. No nitrites/ammonia. Calcium hangs around 640 with my carx, magnesium at 1250, alk 7.5. PH ranges from 8.2-8.3 every day morning to night. I have 4 reefi duo lights with another radeon g5 and hybrid t5s. A little cyano but no turf/gh algae or anything else. I have large enough sized skimmer running 24/7 but it doesn't pull out tons these days. Tanks coming up on two years.

Not really sure if my feeding or bioload is an issue as my nitrates seem fine but i have a small common ray, a vlamingi tang, a louti grouper, purple tang, coral cat shark and a squirrel fish along with about 30 turbo snailies. I feed about 10 silvers a day with a couple cubes of mysis.

HALP PLS

 

[pandaparties]

TDS on my RODI is 0, pretty good about changing them. I've not done a water change in about 1.5 years

 

[EeyoreIsMySpiritAnimal]

What test kits are you using, and have you compared the results on a different brand and/or the same brand with new reagents?

 

[pandaparties]

What test kits are you using, and have you compared the results on a different brand and/or the same brand with new reagents?

Hanna 713 is my goto, and I tried a salifert a bit ago that gave similar results.

 

[mdb_talon]

Agree with double checking with a different test. Getting 2.0 ppm phosphate out of 600g(plus what stores in rocks/substrate gonna take awhile and burn through a lot of GFO).

I know many don't like it because it does have some potential risks, but I would personally be using lanthium chloride to at least get it to reasonable amount then maybe GFO to keep it there

 

[EeyoreIsMySpiritAnimal]

Your nitrates are really low, especially considering your phos level. Have you tried raising that?

 

[Reef.]

PO4 that high will exhaust the gfo within hours, with no corals, you can reduce the po4 much faster, if using a reactor, test the effluent when it increases change the gfo, you shouldn’t have much trouble lower the po4, just make sure not to get to zero.

The reason your po4 increases when you add gfo is because when you remove po4 from the water, po4 from the rock and sand releases.

 

[pandaparties]

Agree with double checking with a different test. Getting 2.0 ppm phosphate out of 600g(plus what stores in rocks/substrate gonna take awhile and burn through a lot of GFO).

I know many don't like it because it does have some potential risks, but I would personally be using lanthium chloride to at least get it to reasonable amount then maybe GFO to keep it there

Any idea the risks on lanthium chloride? My worry is a lot of the things labeled "safe" for most fish aren't well tested with things like rays or sharks. Kind of like copper which can be really harmful to them but are fine with most fish.

It is hard watching like 50$ worth of GFO not make even a dent though. Thanks a bunch for the input!

 

[pandaparties]

Your nitrates are really low, especially considering your phos level. Have you tried raising that?

Oh I thought it was pretty normal levels (though obviously way low compared to po4). I can definitely look into this, thanks!!

 

[pandaparties]

PO4 that high will exhaust the gfo within hours, with no corals, you can reduce the po4 much faster, if using a reactor, test the effluent when it increases change the gfo, you shouldn’t have much trouble lower the po4, just make sure not to get to zero.

The reason your po4 increases when you add gfo is because when you remove po4 from the water, po4 from the rock and sand releases.

Thanks I'll give this a try and checked the effluent. I had no idea GFO would exhaust that fast. Thought it would be a slow process, mind blown

 

[Reef.]

Thanks I'll give this a try and checked the effluent. I had no idea GFO would exhaust that fast. Thought it would be a slow process, mind blown

When you get to 0.03-0.1 the gfo will last for weeks at a time.

 

[mdb_talon]

Any idea the risks on lanthium chloride? My worry is a lot of the things labeled "safe" for most fish aren't well tested with things like rays or sharks. Kind of like copper which can be really harmful to them but are fine with most fish.

It is hard watching like 50$ worth of GFO not make even a dent though. Thanks a bunch for the input!

Some have reported issues with it getting into fish gills I believe once it bonds and turns into a solid. I think especially with tangs. Having said that I have used it for years anytime I have a phosphate issue. I switch to a very very low micron sock and drop very slowly into there and have never had any issue whatsoever.

The other risk with it is it works very well and extremely fast and at times people overdo it and drop phosphate faster than you want to in a reef tank. In a fowlr that is less of a risk but would still go slow with it.

 

[pandaparties]

Some have reported issues with it getting into fish gills I believe once it bonds and turns into a solid. I think especially with tangs. Having said that I have used it for years anytime I have a phosphate issue. I switch to a very very low micron sock and drop very slowly into there and have never had any issue whatsoever.

The other risk with it is it works very well and extremely fast and at times people overdo it and drop phosphate faster than you want to in a reef tank. In a fowlr that is less of a risk but would still go slow with it.

What size sock do you use for yours? I might give this a try if I can't make a dent with the rest of my GFO and just get more GFO for maintenance once it's down

 

[EeyoreIsMySpiritAnimal]

My phone is about to die so I can't re-read this tonight to highlight the parts that might apply, but this article by Randy has some interesting info about alk, pH, calcium reactors, etc in relation to phosphates.

https://reefkeeping.com/issues/2006-09/rhf/index.php

 

[Reef.]

Do you have a skimmer as LC is not meant to be used without one.

 

[mdb_talon]

What size sock do you use for yours? I might give this a try if I can't make a dent with the rest of my GFO and just get more GFO for maintenance once it's down

I use 5 micron sock. It is essentially useless normally because it clogs so fast, but is great for a scenario like this. I had a hard time finding them at online reef stores and ended up buying some polyester felt ones from some sort of industrial supply seller on Amazon.

 

[pandaparties]

Do you have a skimmer as LC is not meant to be used without one.

Yup very large one but thanks for double checking me!

 

[Randy Holmes-Farley]

I don't know if fish care what the phosphate is but coralline might.

 

[pandaparties]

I don't know if fish care what the phosphate is but coralline might.

Oh absolutely which is why I'm asking! I had a bunch before I stopped keeping coral and I have none now (partly from phosphates and I had also seen a lot of my urchins munchin on it too)

I know you're the expert here. Would you agree with GFO/lanthanum chloride? Or is there something else I should be looking at or doing?