How to dramatically lower phosphate? Is this an emergency?

[Guiids]

Hello everyone!



I hadn't checked my phosphate in a while and started growing large amounts of (hair?) algae, see video. I checked and it's sky high!



A few qs:
Is this an emergency?

Where do we think this is coming from? I make my own RO water, could the filters be spent? I'm replacing today.



How can I massively lower this? I assume a huge water change like 80% after I replace filters?



What's the recent opinion on adding solutions to lower phosphate, should I also do that?



Is 1 full fish cube per day too much and causing this creep? See fish and tank size below.



Video of algae/tank:





Tank size: 65 gallon, did 40% water change 2-3 weeks ago, prior to that the tank had not had one 3-4 weeks.



Fish: 2" fox face rabbit fish, inch long box fish, 2 half dollar size damsels, watchman goby/pistol shrimp, cleaner shrimp, 6" engineer goby, 2 urchins (purple spike and long black spike)



Parameters:

Temp 78F

S G 1.027 (adding RO to 1.026)

pH 8.1-8.3

NO3: 75 ppm!!

PO4: 1.03 PPM!!!

Alk: 200 dKH? Using strip

Carbonate: 80 KH ? Using strip

Hardness: 150GH? Using strip



Thank you in advance!

Joe

 

[Randy Holmes-Farley Verified Community Expert]

You likely won't be able or wanting to drop phosphate enough to limit algae without hurting corals, typically, but lowering it slowly is a fine plan (not an emergency).

 

[Garf]

Alk: 200 dKH? Using strip

Hope not.

 

[Randy Holmes-Farley Verified Community Expert]

General hardness is not a useful measure in seawater it is an almost uninterpretable mix of magnesium, calcium and strontium in useless units of measure.

 

[Guiids]

Got it. I actually have an alkalinity meter so I'll test it legit when I get home

 

[Randy Holmes-Farley Verified Community Expert]

Got it. I actually have an alkalinity meter so I'll test it legit when I get home

Well, 200 dKH is not correct,. Even 20 dKH is very much out of the realm of likely.

 

[Pod_01]

Just an opinion, if you are not keeping corals you can bring the PO4 down quickly with GFO etc…

But you do have odd fish selection for 65gal tank. From my understanding Boxfish can be aggressive and need 100/120 gal tank… Damsels can be really aggressive and fox face rabbit fish requires 120gal tank…

I suspect PO4 may be the least of your issues…

Good luck,

 

[Miami Reef]

Hate to be the bearer of bad news, but lowering phosphate won’t reduce hair algae. :(

They can survive with very low phosphate.

The only thing that helped cure my hair algae issue was adding tangs.

 

[Garf]

The only thing that helped cure my hair algae issue was adding tangs.

Just as nature intended;

https://search.app?link=https://ult..._campaign=aga&utm_source=agsadl2,sh/x/gs/m2/4

 

[Guiids]

Just an opinion, if you are not keeping corals you can bring the PO4 down quickly with GFO etc…

But you do have odd fish selection for 65gal tank. From my understanding Boxfish can be aggressive and need 100/120 gal tank… Damsels can be really aggressive and fox face rabbit fish requires 120gal tank…

I suspect PO4 may be the least of your issues…

Good luck,

Yeah I know it may seem concerning, I added them 1 at a time slowly after quarantine, they've been together 10 months, theyre all pretty small and will get a bigger tank as they grow. I watch them regularly. The box fish is actually super chill just helicopters around. The damsels have their spot they protect but they're not overly aggressive at all. The fox face is also real chill and will get between anyone squabbling. Overall it's a peaceful tank it's just getting overrun by algae. Only 'corals' I have are GSP and zoanthids.

 

[Garf]

Yeah I know it may seem concerning, I added them 1 at a time slowly after quarantine, they've been together 10 months, theyre all pretty small and will get a bigger tank as they grow. I watch them regularly. The box fish is actually super chill just helicopters around. The damsels have their spot they protect but they're not overly aggressive at all. The fox face is also real chill and will get between anyone squabbling. Overall it's a peaceful tank it's just getting overrun by algae. Only 'corals' I have are GSP and zoanthids.

Add corals

 

[moretor1]

I believe your test strip is measuring in ppm, not degrees. There's some online calculators to help convert

 

[BristleWormHater]

Hate to be the bearer of bad news, but lowering phosphate won’t reduce hair algae. :(

They can survive with very low phosphate.

The only thing that helped cure my hair algae issue was adding tangs.

100% the only way to get rid of this stuff is to have something eat it and get the tank mature
I've had this torture chamber for gha, just to test how hardy my particular strain is, this is a small container filled with RO water, 0 light, 0 flow. Still alive after two months.

 

[Guiids]

100% the only way to get rid of this stuff is to have something eat it and get the tank mature
I've had this torture chamber for gha, just to test how hardy my particular strain is, this is a small container filled with RO water, 0 light, 0 flow. Still alive after two months.

My tank should be mature it's been established/cycled for a full year? Is there something Im missing?

 

[Miami Reef]

My tank should be mature it's been established/cycled for a full year? Is there something Im missing?

Sometimes it’s just about introducing the algae species to the tank.

My tank did not have any hair algae until the 2 year mark. I assumed the species must of hitchhiked on a coral or shell. The hair algae I had was called derbesia. It’s very resistant to herbivores. I tried snails, urchins, sea slugs, and certain blennies.

The best hair algae controllers IMO are zebrasoma tangs and foxface fish.