Phosphates, Feeding, and Green Hair Algae

[meverha1]

I have a fairly large tank that is 30 inches tall. The uppermost rocks are covered in a thick carpet of green hair algae. It doesn't seem to be growing or spreading but it's not going away either. However, if I pull it it will grow back.

My parameters are normal except that my nitrates are high and my phosphate is 0. I've dosed NoPoX since day one as I used Red Sea "Reef Mature" to cycle my tank. I also have a fuge with healthy growing macroalgae.

Clearly the high nitrates are contributing to the GHA issue and I suspect that my phosphates are 0 because the algae is using all of it. Additionally I'm likely phosphate limited so carbon dosing isn't able to bring the nitrates down. I suspect I need to actually increase phosphate a bit in order to kickstart the bacteria and lower the nitrates.

Here's my question:

Should I be feeding more or less?

I have a 10 fish total including a Hippo tang, yellow tang, and Foxface. All my my fish are fat and happy. I put a square of seaweed on a clip for them daily and give them some pellet food every morning. In the evening I feed frozen - a homemade mush mix that is essentially reef frenzy. They eat most of it but there's always a small bit leftover that floats around the tank until snails get it...

Should I cut back on my feedings a bit in order to get the GHA under control? Maybe switch to every other day feeding? My fish are pigs and always act hungry despite being fat so I can't use them as a good indicator of how much (or how little) to feed.

 

[mcgyvr]

Define "high"?

Have you tried to increase dosing amount?

Another thing to do is simply pull the rocks one at a time over the course of a couple days and soak them in 50% old tank water and 50% hydrogen peroxide while you manually scrub with a toothbrush for roughly 10-15 minutes to get all the GHA off the rock..
But you still need to take care of your nitrate issue..
How large is the tank? What about just a few large normal old water changes to bring nitrates down?

 

[meverha1]

Define "high"?

Have you tried to increase dosing amount?

Another thing to do is simply pull the rocks one at a time over the course of a couple days and soak them in 50% old tank water and 50% hydrogen peroxide while you manually scrub with a toothbrush for roughly 10-15 minutes to get all the GHA off the rock..
But you still need to take care of your nitrate issue..
How large is the tank? What about just a few large normal old water changes to bring nitrates down?

High is greater than 10 ppm. Currently sitting around 30 ppm Nitrates.

Total water volume is around 140 gallons. I'm at the maximum daily NoPoX dose for the amount of water. The dose is delivered in two parts, 12 hours apart so the tank is getting roughly 8 ml of NoPoX ever 12 hours.

I've thought about increasing the dose but I've previously been told that I'm Phosphate limited and that increasing the dose wouldn't likely do much since there needs to be a little Phosphate to "kick off" Nitrate reduction. Do you think adding another 2-4 ml of NoPoX a day would do anything?

Given my rock work and coral placement pulling rock out of my tank and soaking it in hydrogen peroxide isn't really practical. I'd think about dosing small amounts of peroxide but I don't want to kill the shrimp and pods in my tank.

 

[meverha1]

Also, if I stopped offering sheets of Nori daily would that give the tangs and foxfaces incentive to eat the hair algae instead?

 

[meverha1]

Next Question...

If my Phospate level measures 0 (assuming GHA is holding Phosphate), Should I still be running GFO or should I discontinue the GFO?

 

[Sk8r]

Change your GFO medium monthly: it can saturate really fast and then can't absorb anything.

 

[Jazeel55]

Buy a sea hare it's the natural way


Sent from my iPhone using Tapatalk

 

[meverha1]

Change your GFO medium monthly: it can saturate really fast and then can't absorb anything.

Aware of that but that wasn't really my question.

I have hair algae. I also have 0 phosphates according to my phosphate test kit so the assumption is that the GHA is storing/using the phosphate.

I also suspect that the 0 phosphate level in my tank is limiting export of nitrate via carbon dosing.

In the scenario above, should I run GFO or not? If so, why? If not, why?

 

[rjjr1963]

In my opinion your phosphate is way too low. How are you measuring it. The Redfield scale would suggest a 16 to 1 ratio between nitrate and phosphate. His hypothesis says it isn't the actual levels that are important but rather the ratio between the two to keep algae low.

 

[meverha1]

I know it's low. Trying to figure out how to raise it safely.

Any ideas?

 

[rjjr1963]

I know it's low. Trying to figure out how to raise it safely.

Any ideas?

Potassium phosphate.


There is a calculator here to determine dosing. Was helpful for me to read the entire article.

https://buddendo.home.xs4all.nl/aquarium/redfield_eng.htm#calculator

 

[R1ant04]

Id b willing 2 bet that ur lights r either 2 close 2 the waterline or 2 much white(go more blue) or photo period is 2 long. And as mentioned by Jazeel..a dolabella sea hare would eat it, just might b slow about it at 1st. If ya do get tha sea hare b ready 2 trade or sell it after all the hair is gone cause it will starve.

 

[mcgyvr]

I would discontinue the GFO...

 

[Braves95]

I would cut back on feeding. On my tank I feed algae sheets twice a week.I have an Atlantic Blue and Hippo tang and chaeto in my fuge. I have zero hair algae in my display tank. I am also running skimmerless and that seems to be feeding the macro algae as there are increased nutrients for the macro algae.

 

[meverha1]

I would discontinue the GFO...

It's been discontinued for about a month now and I've seen no change.

Id b willing 2 bet that ur lights r either 2 close 2 the waterline or 2 much white(go more blue)

I'm using the Coral Lab settings for LPS coral, which has whites at 15 and a full spectrum of blues. It does set green at 20 and red at 25. Wondering if maybe I should bring those numbers down a bit. I've heard that red light can contribute to algae.

I would cut back on feeding. On my tank I feed algae sheets twice a week.

How often do you feed pellet or frozen food? I offer algae sheets daily an my fish rarely eat the whole thing. They just nibble and it just hangs on the clip all day until I take it out at night. Maybe I should cut it back to every three days to get them to the point where they eat the whole thing quickly?

Also wondering if I should cut back my frozen feeding to every other day...

 

[Braves95]

How often do you feed pellet or frozen food? I offer algae sheets daily an my fish rarely eat the whole thing. They just nibble and it just hangs on the clip all day until I take it out at night. Maybe I should cut it back to every three days to get them to the point where they eat the whole thing quickly?

Also wondering if I should cut back my frozen feeding to every other day...

Flake food everyday (1 pinch)
Frozen and pellet alternate every other day (1 cube/pinch)
Algae sheet 2 times a week