How much PO4?

bdare · Sep 27, 2019

Hello all,

I apologize if this is one of those questions that gets asked on a regular basis, but I can't seem to find any definitive answers. I have a relatively new tank (5 months). Current inhabitants are fish and a few snails and crabs. The only coral is a green leather toadstool which is doing really well. I've been growing cheato like crazy and I'm trying to get the tank ready for more coral including SPS.

I'd like to know how much phosphate am I supposed to have in the tank? I just checked it with a HANA ULR and got a value of .07ppm. I've seen where NSW is double that.

Also.... the only nitrate test kit I have is one from Salifert. I had a buddy bring some of his water over a week ago. I tested his water and it was HIGH (50+). Then he took his water to a fish store and they said it was 3.

My nitrates have been testing in that same 50+ range and don't seem to budge. I'm wondering if it's a bad kit so I just ordered the Red Sea Pro kit.

If my nitrates are indeed that high should I be dosing phosphate to get the nitrates to drop (based on the Redfield ratio)?

What is the target range for PO4 in a mixed reef?

Thanks,
Ben

Skynyrd Fish · Sep 27, 2019

Ben your tank is still young. Your on the right track with cheato. Are you using ro/di water? I would keep up with a 10% weekly water change and keep growing the cheato. I’d wait for your new test kit to double check your no3. How deep is your sand? What type of filter are you using? Filter floss and bio balls can be a nitrate factory. Post a pic of your tank.

Skynyrd Fish · Sep 27, 2019

I didn’t answer your question sorry. I would double check the no3. Po4 below .1 is generally good. No3 above 1 to 5 is a good target IMO. you Don’t want an algae bloom. If you decide to dose po4 I’d go with baby steps. There is of course tanks that are awesome with way higher, and lower levels.

bdare · Sep 27, 2019

Ah. Sorry. I guess I should have also provided more information.
I have about 15 years of cumulative reef keeping experience. My last tank was a 120 gallon mixed reef.

You can see pictures of my old tank here in my build thread:

Large Build - BDare's 210 Mixed Reef

Hello all, Long time R2R lurker here. Been keeping aquariums my whole life and reef tanks since about 2005. Six years ago I shut down a 120 and I've been missing it ever since. The bug has got me and now I'm planning a new 210 gallon tank. Equipment Tank - 210 Gallon Planet Aquaruims 72L x...

www.reef2reef.com

Definitely using only 0 TDS RO/DI water. Have a reactor which is only running ROX carbon. I have 2 7" filter socks which I replace on a weekly basis. I have a Regal 200 protein skimmer. Fuge is lit with a Kessil H380.

Water is crystal clear. The only algae that's growing in the display is green coralline. Nothing fuzzy or gross that I can see, but the tangs and snails would probably knock it down if it did show up.

With all the green coralline growth I've had to dose alk a few times.

Calcium - 480 (Salifert)
Magnesium - 1440 (Salifert)
Alk - 8.4 DKH (HANA)

Last time I had a tank was in 2012. Back then I had never heard of the Redfield ratio. Never had a problem with Nitrates or Phosphates. At that time the HANA checkers were just becoming popular in the hobby. I never owned them. My Nitrates and phosphates always read undetecable with Salifert kits.

I've always been able to keep really low nitrate with not over feeding and Cheato. Now that I'm in the loop on Redfield just wondering if dosing phosphate would help bring the nitrates down.

I'll be using a GEO Calcium reactor to maintain parameters once I start adding hard coral.

SeaDweller · Sep 27, 2019

Just do water changes to bring your NO3 down. You don't need to dose anything. Your PO4 level is fine, and try not to chase some magic numbers; let your tank talk to you. With SPS you DONT want low nutrients anyway, but if I were you, I'd get on massive water changes to bring that NO3 down, if it's that high.

bdare · Sep 27, 2019

SeaDweller said:
Just do water changes to bring your NO3 down. You don't need to dose anything. Your PO4 level is fine, and try not to chase some magic numbers; let your tank talk to you. With SPS you DONT want low nutrients anyway, but if I were you, I'd get on massive water changes to bring that NO3 down, if it's that high.

Not sure I agree with this approach as there are multiple sources that say water changes are not a viable method for nutrient export. I'm honestly not trying to chase any magic number. Just wondering if I'm phosphate deficient for adequate nitrate reduction the natural way.

SeaDweller · Sep 27, 2019

bdare said:
Not sure I agree with this approach as there are multiple sources that say water changes are not a viable method for nutrient export. I'm honestly not trying to chase any magic number. Just wondering if I'm phosphate deficient for adequate nitrate reduction the natural way.

how so? if you have 50 ppm NO3 and you remove half of the water volume and replace it with the same volume with no NO3, what would one think is left? 40 ppm? at one point my tank was 300 ppm NO3. I did 4-5 120 gallon water changes on my 240 in about 1.5 weeks. my NO3 was about 10-15 when I was done. Hows that not viable?

people forget the power of regular WC.

Jay Z · Sep 27, 2019

I'm going to assume you had 7ppb on the hanna ulr checker. 7ppm would just give you a high level indication.

If it was 7, thats good. Anything under 10 ppb, (.031 ppm) is the "happy" target range, so they say.

Skynyrd Fish · Sep 27, 2019

The old tank looks sweet. I’ll be looking forward to seeing this one rocking.

bdare · Sep 27, 2019

Jay Z said:
I'm going to assume you had 7ppb on the hanna ulr checker. 7ppm would just give you a high level indication.

If it was 7, thats good. Anything under 10 ppb, (.031 ppm) is the "happy" target range, so they say.

That sounds right.... the HANA checker said point oh seven ppm. If my decimal math is right that sounds like 7ppb.

Do you think I have enough phosphate to bring nitrates down or should I add some?

ZaneTer · Sep 27, 2019

SeaDweller said:
how so? if you have 50 ppm NO3 and you remove half of the water volume and replace it with the same volume with no NO3, what would one think is left? 40 ppm? at one point my tank was 300 ppm NO3. I did 4-5 120 gallon water changes on my 240 in about 1.5 weeks. my NO3 was about 10-15 when I was done. Hows that not viable?

people forget the power of regular WC.

Hi SeaDweller

Mathematically you are correct.....BUT.....you haven’t taken into account the amount stored in sand or rock work. You may find you dropped from 100ppm to 50ppm immediately after a 50% water change but 3 hours later you could be straight back up to 90ppm.

You see how it quickly becomes a non viable route.

SeaDweller · Sep 27, 2019

ZaneTer said:
Hi SeaDweller

Mathematically you are correct.....BUT.....you haven’t taken into account the amount stored in sand or rock work. You may find you dropped from 100ppm to 50ppm immediately after a 50% water change but 3 hours later you could be straight back up to 90ppm.

You see how it quickly becomes a non viable route.

I guess my results dont lie. days in between my water changes kept cutting them in half, and then I eventually bottomed out at 1.0ppm. So, that doesn't explain what happened to me, and if that were the case, I'd still be doing water changes probably.

But hey, what do I know?

ZaneTer · Sep 27, 2019

You either have absolutely no nutrient reservoir in your sand or rock with all nutrients in circulation in the water column

Or

You are mistaken.

You may take your pick.

Justfebreezeit · Sep 27, 2019

I find phosphates are hard to rid of with water changes, nitrates have always been easily remedied with water changes for me.

ZaneTer · Sep 27, 2019

bdare said:
Hello all,

I apologize if this is one of those questions that gets asked on a regular basis, but I can't seem to find any definitive answers. I have a relatively new tank (5 months). Current inhabitants are fish and a few snails and crabs. The only coral is a green leather toadstool which is doing really well. I've been growing cheato like crazy and I'm trying to get the tank ready for more coral including SPS.

I'd like to know how much phosphate am I supposed to have in the tank? I just checked it with a HANA ULR and got a value of .07ppm. I've seen where NSW is double that.

Also.... the only nitrate test kit I have is one from Salifert. I had a buddy bring some of his water over a week ago. I tested his water and it was HIGH (50+). Then he took his water to a fish store and they said it was 3.

My nitrates have been testing in that same 50+ range and don't seem to budge. I'm wondering if it's a bad kit so I just ordered the Red Sea Pro kit.

If my nitrates are indeed that high should I be dosing phosphate to get the nitrates to drop (based on the Redfield ratio)?

What is the target range for PO4 in a mixed reef?

Thanks,
Ben

Ben, your PO4 level looks pretty good and I definitely wouldn’t worry about it. Just wait for the new test kit to arrive before worrying about NO3.

On a side note presence of nitrite is known to skew nitrate rest results heavily making it seem as if you have very high nitrate.

I aim for 0.05-0.08ppm PO4

some people like @Chaswood79 have higher levels with excellent success.

Charlie’s Frags · Sep 27, 2019

Chaeto and water changes work great for reducing no3.

bdare · Sep 27, 2019

Chaswood79 said:
Chaeto and water changes work great for reducing no3.

Cheato can only reduce nitrate if you have enough phosphate. How much phosphate do I need to reduce my elevated nitrate?

SeaDweller · Sep 27, 2019

ZaneTer said:
You either have absolutely no nutrient reservoir in your sand or rock with all nutrients in circulation in the water column

Or

You are mistaken.

You may take your pick.

Say what you want. Do what you want. I know what works, so I stick to it. There’s no mistaking anything and I’m far from mistaken.

If that’s your attempt at insulting my intelligence, try again.

Halal Hotdog · Sep 27, 2019

I am a big fan of carbon dosing to lower nitrates. I feed very heavily and with chaeto, ATS, and skimmer my nitrates can get wildly high. Takes a few weeks to kick in, but once it does the nitrates drop rapidly.