Phosphates in fish less aquarium

[Grnorton]

Ok, so it's been 3 weeks since I moved my 90 gallon reef tank. I used the same cycled live rock and same sand, but I rinsed the sand and added 30 new pounds and got rid of probably 40% of old sand. The tank has been up and running for 3 weeks. All parameters are testing 0 except my phosphates. I use a hannah checker and get an average reading of 55 or .17 phosphate levels. I don't understand. I have phosguard running in a reactor and my goal is to keep sps but even with changing out the phosguard 3 times in 3 weeks have seen zero results. Any words of wisdom. Thanks

[Grnorton]

also forgot to mention that I do have some brown stringy algae growth as well as some lime green hair algae. nothing out of control just, its there.

[tmz]

I'd guess teh old sand is leaching it and/or producing some organic decay. Any ammonia?

[anthonys51]

did u have a algae phosphate problem in the old tank

[Grnorton]

i bought the phosphate test after the move, so no idea on the phosphates, but i never had a single strand of algae. and zero ammonia, or nitrates

[Grnorton]

bump. anyone?

[CStrickland]

How long was the old tank running for?

[bertoni]

I might look into dosing lanthanum chloride. If the old sand is leaching phosphate, you might need to spend a lot of money on PhosGuard before the level drops. Also, getting a second opinion on the test kit might be useful.

How much PhosGuard does the tank have running?

[Grnorton]

Old tank was running for 6 months and it has about a cup steadily tumbling in a reactor.

[bertoni]

With the phosphate level that high, the GFO might be saturated in a few days, or even less. I'd measure the phosphate level of the reactor output. When that matches the tank level, I'd replace the media. If the cost seems to be a bit high, lanthanum chloride can remove phosphate at a much lower cost.

[BigJohnny]

If your in a fishless aquarium just use lanthanum chloride, there are no fish for it to harm and it is much more cost effective than gfo. It's also possible your hanna is contaminated and your not cleaning it properly.

[CStrickland]

That seems high for 6 months. Like, I dunno, I would think a lot of what came in on the rock would've leached out, and your levels'd have to be really high for it to soak so much up.

Is the lime green stuff soft like algae or rocky like coralline? Curious cause high phosphate usually means more algae less coralline I think

[Grnorton]

It's lime green hair algae of some type. Not dense like typical hair algae. But definitely hair algae

[Icefire]

I'd guess teh old sand is leaching it and/or producing some organic decay. Any ammonia?

+1

I would remove the sand myself, I never keep old sand

[Grnorton]

Tons of phosguard later I'm down to .02 phosphates all is well

[bertoni]

Okay, that sounds a lot better. :)

[Grnorton]

How long will it take the algae to die out...it's dying but slowly yyyyy lol this is my first real algae problem...

[bertoni]

That's hard to predict. There are a number of variables involved, and we lack the precision in our testing equipment that'd be required to understand what's happening.