No detectable PO4 and lots of algae

[bbqjon]

Hello, Jon here.
I have a 6'x2'x2' reef tank and need some advise. I obviously have a lot to learn. Phosphate not detectable via Salifert test. However, I have a lot of green algae on the live rock. I have been told to get a small GFO reactor. I have also been told to just use some Microbacter Clean in stead since it it such a small amount being scavanged by the algae. What should I do?

 

[Sk8r]

It may be regular hair algae, which feeds on phosphate, or bryopsis, which looks much the same except that it develops in strings and plumes. Bryopsis can be fought with a preparation called Reefflux, but the simplest and likeliest in a new tank is hair, which can be handled via phosphate uptake. The lack of phosphate may be due to it all being IN the algae, and more slowly released by rock and sand, which often contain it. I'd try the phosphate reduction first.

 

[Timfish]

How old is your system? What animals do you have to eat the algae? Various algae cycles, colloquially called "the uglies", are normal during the maturing process and often happen after tank moves and if there have been disruptions to the ecosystem like power outages or equipment failure. I only use manual removal to deal with nuisance algae in my maintenance business and over the decades have not seen any correlation between PO4 and nuisance type algae. If you have corals I would not be dropping phosphates but adding phosphate to have some measurable PO4, prefferably above .03 mg/l.. Corals need phosphorus and are competing with algae for it. Stripping out phosphate can have very deliterious effects on corals potentially killing them as well as making it easier for algae to compete. Here's quotes by J. E. N. Verone and Charles Delbeek, two of the formost authorities on corals and some links if you're interested in reading further:

"Our crystal-clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127

"Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus (.2 mg/l) and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30


https://therichross.com/skeptical-reefkeeping-ix-test-kits-chasing-numbers-and-phosphate/

https://www.cambridge.org/core/jour...reef-corals/AFB1CF4CB68823BD13AD254623FD3C7C#
An Experimental Mesocosm for Longterm Studies of Reef Corals

Phosphate Deficiency:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching:
https://www.nature.com/articles/nclimate1661

Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
https://www.frontiersin.org/articles/10.3389/fmars.2015.00103/full

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://www.sciencedirect.com/science/article/pii/S0025326X17301601?via=ihub

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach
https://www.sciencedirect.com/science/article/pii/S0022098111004588

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
http://jeb.biologists.org/content/214/16/2749.full

Phosphorus metabolism of reef organisms with algal symbionts
https://esajournals.onlinelibrary.w...98e60zfBEvx5IcIVGhmlpUYmzIJuqUNVm0sG8_0vth6lq

 

[Michael Hoaster]

What do you currently have that eats algae? I like a diverse selection of reproducing snails to start. Since your tank is big enough, you are free to add Tangs, which can also help. But add smaller, more timid fish first.

Welcome to RC Jon!

 

[bbqjon]

What do you currently have that eats algae? I like a diverse selection of reproducing snails to start. Since your tank is big enough, you are free to add Tangs, which can also help. But add smaller, more timid fish first.

Welcome to RC Jon!

Hi Michael, thanks for the post! I have a low bio load at present. One flame angel, 2 yellow tail damsels, 2 clowns, and a medium sized blue hippo. All snails and crabs seem to have died out. What tang and snail selection would you add if this were your tank? DT is probably 165 gallons after live rock displacement.

 

[Michael Hoaster]

I like the reproducing Mini Strombus snails. They stay small, so they can go anywhere. Indo-Pcific Sea Farms Sells them on their Facebook page. Also, I recommend getting rid of all hermit crabs, because they kill snails for their shells, and are inferior algae eaters. Once they get a taste of fish food they're useless.

As for which tang, I'd ask what kind of algae do you have?

 

[bbqjon]

I like the reproducing Mini Strombus snails. They stay small, so they can go anywhere. Indo-Pcific Sea Farms Sells them on their Facebook page. Also, I recommend getting rid of all hermit crabs, because they kill snails for their shells, and are inferior algae eaters. Once they get a taste of fish food they're useless.

As for which tang, I'd ask what kind of algae do you have?

Hi Michael, I have gone the hermit crab and snail route before, and like you say, the hermits ended up killing off many of the snails. I don't have a clean up crew. I have one blue hippo tang. I'll look into the Mini Strombus snails. As for the algae, it appears to be hair algae based on what I have read about the different types.

 

[Michael Hoaster]

Hair, or filamentous algae is is the favorite food of the Zebrasoma tangs, like the Yellow and Scopas. The blue tang is one of my all time faves. Great fish!

Clean up crews are vital, in my opinion. Otherwise YOU are it. There are several, great, reproducing snails available, so you can have a diverse selection, with different specialties. Ceriths, Nerites and Nassarius come to mind. For the sand bed, your tank should be able to support a sea cucumber and a fighting conch. Mini brittle stars reproduce and are great detrivores. And pods can help too.

I think it's best to build up diversity in aquariums from the bottom (of the food chain) up. We can use Nature as an ally, rather than adversary. It's ready and willing to help. We just have to learn how best make use of it.

 

[Oldreeferman]

Hello, Jon here.
I have a 6'x2'x2' reef tank and need some advise. I obviously have a lot to learn. Phosphate not detectable via Salifert test. However, I have a lot of green algae on the live rock. I have been told to get a small GFO reactor. I have also been told to just use some Microbacter Clean in stead since it it such a small amount being scavanged by the algae. What should I do?

How long has tank been cycled? Would help to know as its hard to remove & keep in check the ugly hair algae stage right after the 1st cycle takes time.