How do giant aquariums manage phosphate levels?

[Miami Reef]

They have all sorts of corals and fish in these massive tanks. How do they keep their phosphates low? My tank is about 300 gallons, and I’m dosing seaklear pool phosphate. About a capful next to my skimmer. It clouds the water for about an hour or two but I’m still getting an algae film.

I bet those big tanks don’t get that many water changes. I get about 75% water change once a month with NSW. That’s all I will spend with water changes.

 

[csb123]

I have the same size of tank and use Seaclear as well. I find GFO doesn’t give me consistent results over time, hard to get the volume correct, and very expensive. I tested PO4 daily for a month and came to a daily dose of 1.7 ml. With this small volume it doesn’t cloud the water.

 

[Miami Reef]

I have the same size of tank and use Seaclear as well. I find GFO doesn’t give me consistent results over time, hard to get the volume correct, and very expensive. I tested PO4 daily for a month and came to a daily dose of 1.7 ml. With this small volume it doesn’t cloud the water.

Do you dose in with 5mm socks, or just in water?

 

[csb123]

I dose in my refugium which drains to my sump. No socks. My tangs appear unaffected.

I also have an automatic continuous water change of 12% per week.

 

[csb123]

The lanathum precipitate is inert and the only unconfirmed potential side effect is irritation to tangs gills. It is widely used.

 

[tapeworm123]

First check ur rodi water, tds meters can’t meter phosphate. A lot of us reefers have gfo on our rodi units .

 

[S2G]

I'm a refugium believer.

This might be helpful

How to reduce Phosphate

Hi everyone I have 600 liters of aquarium and some corals (star polyps and zoanthides and mushrooms) and twelve fish (yellow, blue, dischardeny tanks, two dart fish, goby, one copper band butterfly, two perculas, one neon, two damsels) feeding them two times in a day for about a year and have...

www.reef2reef.com

 

[tapeworm123]

I'm a refugium believer.

This might be helpful

How to reduce Phosphate

Hi everyone I have 600 liters of aquarium and some corals (star polyps and zoanthides and mushrooms) and twelve fish (yellow, blue, dischardeny tanks, two dart fish, goby, one copper band butterfly, two perculas, one neon, two damsels) feeding them two times in a day for about a year and have...

www.reef2reef.com

Yes this definitely helps but in my opinion it can’t keep up if the issue is rodi water/tap off water has a lot of phosphate.

 

[Sallstrom]

When having a good ratio/balance between mass of coral, fish and macro algae, it doesn't have to be that hard to keep a low level of phosphate. I've been responsible for reef tanks at 2600 and 6800 US gallons and used mostly GFO to keep PO4 at 0,02-0,06 ppm(almost no WC). I also used LaCl in the start up phase(lots of dry rocks), but didn't need to use it when things started to grow. So IMO it's most practical to stock the tank slowly and find the right amount of fish vs coral+macro algae.

 

[tapeworm123]

When having a good ratio/balance between mass of coral, fish and macro algae, it doesn't have to be that hard to keep a low level of phosphate. I've been responsible for reef tanks at 2600 and 6800 US gallons and used mostly GFO to keep PO4 at 0,02-0,06 ppm(almost no WC). I also used LaCl in the start up phase(lots of dry rocks), but didn't need to use it when things started to grow. So IMO it's most practical to stock the tank slowly and find the right amount of fish vs coral+macro algae.

Great response here, only thing I can add is gfo is a lot more safer then LaCI due to LaCI can strip the water of phosphate way faster then gfo causing corals to be stressed or even bleach IMO.

 

[Snoopy 67]

PO4 levels @ the 20,000 gallon tank on LI run around .16 so I've been told.
Lanthanum Chloride is used occasionally along with GFO running 24/7.

 

[csb123]

Great response here, only thing I can add is gfo is a lot more safer then LaCI due to LaCI can strip the water of phosphate way faster then gfo causing corals to be stressed or even bleach IMO.

This is true. That’s why I tested daily for a full month to find a safe daily dose. As to GFO, many have had big issues with it as well.

For myself I use multiple nutrient reduction methods. Chaeto refugium, skimmer, and automatic water changes.

I also use Lanathum to fine tune phosphate levels, and occasionally DIY NOPOX for nitrate.

 

[Sallstrom]

Yes, I forgot to mention carbon source. We did bring down the phosphate level in 6800 gallons with the addition of a carbon source and potassium nitrate. Worked great and we were able to lower the PO4 level slowly.

 

[Treefer32]

I have a 350 gallon aquarium with 75 gallon sump. I do 40 gallon water changes twice a month using basic instant ocean salt. I make sure my RODI is 0 TDS and change it out as often as I need to. I had a crash early on due to a bad heater and lost 16 fish. Most of their corpses were inside rocks. The fish went and hid and I couldn't get to them. With all the decay and stuff I had a break out of some hair algae. Now 5 months after that crash (and my tank is a total of 10 months old). All hair algae has died off and now I have around 10 fish, several of them in the 6-8 inch size. I feed around 3 frozen cubes of food per day plus a sheet of nori two - three times a week.

How did I manage it - I managed it with a turf scrubber. When fish were decaying I had so much hair algae growing on my scrubber that it was bursting at the seems within 3 days. I had to clean a softball sized ball of hair algae off the scrubber every 3-4 days. It was crazy. I did 10% water changes every week in addition to cleaning the scrubber twice a week. Now, the scrubber has slowed down. It's full of a nice dark green softball sized bunch of hair algae in 7-8 days tops. The tank has stabilized and things are going great. The fish are doing amazing, and the corals are loving the nitrates. I tested for nitrates this weekend just to see where things stabilized at and with the red sea pro they were something between 1 and 2. Which, I'm good with. I've got my ph stabilized at 8.1 and swings up to 8.2 now between the scrubber scrubbing CO2 out of the tank and introducing O2 and the baked baking soda I dose.

My goal is around 30 fish, some of them larger - Like a few Genicanthus angels that get up to 8-9 inches. But, I feel like I have ways to export nutrients. Now, can my process scale? That I don't know yet. At what point will I have more fish or more feeding than what the scrubber / skimmer / water changes export? I don't know how large aquariums do it, but, this is what is working for me so far!

That's a great question!

 

[Daniel@R2R Verified Admin]

Great discussion!

 

[vetteguy53081]

For my large tank, I use NP-active pearls beads. Keeps it controlled well

 

[Hans-Werner]

We did bring down the phosphate level in 6800 gallons with the addition of a carbon source and potassium nitrate.

Hi Sallstrom,

Which carbon source did you use? Alcohole like vodka is unbelievable expensive in Scandinavia.

 

[Sallstrom]

Hi Sallstrom,

Which carbon source did you use? Alcohole like vodka is unbelievable expensive in Scandinavia.

Hi Hans-Werner!

We're using 96% Etanol. The same as we use in our DNA lab. But we dilute it to about 40% before we use it in aquariums. It's not that expensive, compared to Vodka
I think most of the carbon sources, even those only made for aquariums, are really expensive..

Another reason why I prefer 96% etanol for labs, is because I know what's in it. I'm moving away from "magic bottles"..

Edit. And I think our administration would be upset if we bought Vodka..

 

[RedSea500MaxS]

For my large tank, I use NP-active pearls beads. Keeps it controlled well

Vetteguy....but don’t the biopellets also wipe out your NO3 to 0ppm, and PO3?

I tried a biopellet reactor and both went to O fast, and reading you experts blogs most prefer ~10 NO3, and <0.3 P....as you know being way more expert, surely than me.

Thank you....my algae refuge controls my NO3...but still struggle with my PO3. Ideas besides GFO? Which is inconsistent and I agree expensive.

Anyone for cheap source of GFO ? Thx.

 

[Sallstrom]

Vetteguy....but don’t the biopellets also wipe out your NO3 to 0ppm, and PO3?

I tried a biopellet reactor and both went to O fast, and reading you experts blogs most prefer ~10 NO3, and <0.3 P....as you know being way more expert, surely than me.

Thank you....my algae refuge controls my NO3...but still struggle with my PO3. Ideas besides GFO? Which is inconsistent and I agree expensive.

Anyone for cheap source of GFO ? Thx.

Yes, biopellets works the same way as a liquid carbon source. But it's solid.
What you can do is add nitrate to make sure there's still some left in the water, while lowering the phosphate.

10 ppm nitrate and 0,3 ppm phosphate sounds quite high to me, if you want to have corals like Seriatopora for example. But that's just my observations.