0.0 Nitrate & Phosphate

[Adrian Em]

Just want to get some perspective on how to proceed. Tank is a 72 gallon bow-front. Total stocking is 7 fish: 1 clown, 1 fire goby, 1 flame hawk, 1 melanaurus wrasse, 1 yellow Coris wrasse, 1 hippo tang, 1 unknown aggressive purple fish.

I’m a bit new to the hobby. Tank has been running for 1.5 years. Everything looks fine, but haven’t been able to get my nutrients above 0.0 for the last six months. I have no nuisance algae. Corals are growing, not sure if they are growing slowly. Only issue is the acropora do not have good coloration.

The question is; should I worry about the nutrients or just let it be? I feed 1-2 times a day, spirulina mysis and pellets, mostly pellets. Fish look healthy and thriving. No real issues except for maybe a little brown on the sand at times, but it has never become too unsightly or taken over the tank. I’ll post a picture. Any feedback welcome.

 

[Pistondog]

How are you testing?

 

[Adrian Em]

How are you testing?

Hanna checkers for all testing except for Mag (Salifert).

 

[gbroadbridge]

Just want to get some perspective on how to proceed. Tank is a 72 gallon bow-front. Total stocking is 7 fish: 1 clown, 1 fire goby, 1 flame hawk, 1 melanaurus wrasse, 1 yellow Coris wrasse, 1 hippo tang, 1 unknown aggressive purple fish.

I’m a bit new to the hobby. Tank has been running for 1.5 years. Everything looks fine, but haven’t been able to get my nutrients above 0.0 for the last six months. I have no nuisance algae. Corals are growing, not sure if they are growing slowly. Only issue is the acropora do not have good coloration.

The question is; should I worry about the nutrients or just let it be? I feed 1-2 times a day, spirulina mysis and pellets, mostly pellets. Fish look healthy and thriving. No real issues except for maybe a little brown on the sand at times, but it has never become too unsightly or taken over the tank. I’ll post a picture. Any feedback welcome.

The danger with low nutrients is slow starvation of desired organisms, and the possible proliferation of undesirable organisms.

Which test kits are you using?

 

[robotrash]

I think most people would probably say that if you're happy with the state of your tank then don't mess with anything.. I am a returning aquarist though and things have changed a bit since I dabbled last. I've been recommended NeoPhos and NeoNitro to bump those numbers a bit. I haven't started using them myself, however.

 

[Pistondog]

If you are sure of the low levels, id feed reef roids, mostly phosphate, a couple times a week and dose some sodium nitrate.

 

[Adrian Em]

The danger with low nutrients is slow starvation of desired organisms, and the possible proliferation of undesirable organisms.

Which test kits are you using?

Hanna checkers. Wouldn’t the undesirables show up by now? Just trying to gage if I’m in the good now or do I still need to be worried?

 

[Adrian Em]

I think most people would probably say that if you're happy with the state of your tank then don't mess with anything.. I am a returning aquarist though and things have changed a bit since I dabbled last. I've been recommended NeoPhos and NeoNitro to bump those numbers a bit. I haven't started using them myself, however.

I considered that, but then you have the folks that say it’s insane to add nitrate and phosphate to the tank. I’ve tried heavy feeding (3+ times per day) still pegged at zero…

 

[gbroadbridge]

Hanna checkers for all testing except for Mag (Salifert).

In that case the numbers are probably accurate.

To prevent problems you could either use a commercial bottled Nitrate and Phosphate additives to keep nutrients at a reasonable level, or feed more which is a bit less controlled.

Another alternative is to make some DIY solutions using Cacium/Sodium Nitrate and Sodium Phosphate which is what I use. Cheap and very controllable.

 

[gbroadbridge]

I considered that, but then you have the folks that say it’s insane to add nitrate and phosphate to the tank. I’ve tried heavy feeding (3+ times per day) still pegged at zero…

Science marches on ...

It's pretty mainstream now to use additives to control tank nutrients and prevent problems.

 

[SliceGolfer]

Your tank looks healthy and stable. Yes some corals are a little pale but is that nutrients or lighting? Agree with others that you may need to dose N03 & P04 if you want those levels to increase. Personally I like calcium nitrate and trisodium phosphate from Loudwolf. Whatever you choose, go slow and let the corals tell you what they need. I see your wavemakers have a good amount of coralline on them. A dip in citric acid might be a good idea if flow is compromised. Good luck with how you move forward!

 

[jda]

Why would you want to add nitrates and phosphates? It is doubtful that the nitrates help corals and inverts at all and the po4 is not growth growth limited over a few PPB. The only reason that I can think of is to grow-limit (high side) dinos and you do not have any.

If everything is growing OK, then the corals are not nitrogen or phosphorous starved. If you are worried, then just feed the fish more. Fish waste has more available forms of nitrogen and phosphorous than the waste products of nitrate and phosphate.

My guess is that sandbed developed a good population of anoxic bacteria which turn nitrate into nitrogen gas, thus completing the nitrogen cycle. If this is true, then even if you dose the sandbed bacteria will multiply and you will be near zero again soon. This is of no consequence since nearly all inverts in your tank will prefer to ammonia and nitrite to nitrate, if they can even use nitrate at all. Most hosts have to convert nitrate back to ammonia to use it which costs about an extra 30-70% in energy - some cannot convert it at all.

 

[Pod_01]

What do you use on the filtering side? Skimmer and ….
To get the PO4 or NO3 up you might be able reduce the filtering.

Also you could consider using good quality coral foods. Alternatively consider feeding fish more…

Adding NO3 or PO4 is not the best path… easy to get the values up but it might lead to other problems.

 

[Spare time]

Add something like vitachem marine to the pellets. The corals will get the leftovers to counter the 0's and the fish get extra nutrition.


One thing I also do if I get 0's is just add a pinch of flakes or pellets when I walk by the tank

 

[FrugalReefer]

Tank looks good and you’re getting great coralline growth. I wouldn’t worry about it. I would just make sure to keep feeding heavy. Maybe add a few more fish to increase your bioload. Also, what is your alkalinity? With low nutrients like yours I would make sure that alk never goes above 8.0. Personally, I would stay in the range of 7.0-8.0.

 

[jda]

What do you test your no3 and po4 with? If you can get 1-5 ppb on Hannah Ultra Low Phosphorous, then you are not growth limited. If you have .1 nitrate, then you also should be good - mostly since your corals and stuff will get nitrogen from other sources.

If you just see "clear" on a color test kit, this is probably not zero.

I have low po4 and no3 levels like these. They tank just does it - sand takes care of no3 and I have a lot of skimmers and a fuge which grows chaeto like crazy. I do keep my alk around 6.6-7.0. You can get burnt tips on some corals if the levels get truly close to zero, but you usually have to use chemicals and media to get this low - natural stuff will always leave enough, it seems. Calcification is faster when no3 and po4 are lower and you see this with your nice coralline growth. The corals can calcify faster than they can find nitrogen and phosphorous to build new organic tissue, so the skeleton literally outgrows the tissue. Again, this is usually in systems where organic carbon or some other chemicals are used to strip all forms of nitrogen (not just nitrate) - ZEOVit systems could get like this if people do not do it right.

 

[paragrouper]

Before you start dosing stuff, I would recommend feeding a bit more. Maybe give those nice corals some chow too.

 

[Randy Holmes-Farley Verified Community Expert]

IMO, the hobby is all about tweaks to improve the tank. IMO this tank looks quite nice, but that doesn't mean it might not be better.

IMO, it's a fine experiment to add more nutrients by dosing them or by feeding more, and see if things look better or not after a week or so.

N can be dosed as sodium nitrate, calcium nitrate, amino acids, ammonium chloride, or ammonium bicarbonate. I think it is yet to be proven whether dosing ammonium or amino acids are better than dosing nitrate.

P is easily dosed as sodium phosphate.