Coral and Nutrient Levels

[sundog101]

I have a 29g biocube and recently installed an algae scrubber to help deal with some algae issues. Currently my nitrate levels are 5 ppm and phosphate is 0. I'd like to get my nitrates close to 0, but will this affect my soft and lps corals? I've heard stories of soft and lps slowly dying in low nutrient tanks. Can this happen? And if so, how do people keep soft corals in very low nutrient sps tanks? Thanks!

 

[Diesel]

No3's close to 0 or undetectable is a nono for long term.
It won't harm your corals but long term your softies are melting away as SPS turn light to pastel colors.
Hand feeding or spot feeding is your best bet in a UNL system to hold your softies.
Try to bring your No3 down and to do so you can raise your Po4 by feeding, if you do it controlled the ecosystem what you trying to create will balance out over time.

 

[Randy Holmes-Farley]

How are you measuring phosphate? 0 means different things with different methods.

 

[Diesel]

How are you measuring phosphate? 0 means different things with different methods.

Randy, I really don't as I rely on a little bit film algae on my glass everyday and that tells me I'm ok on my levels as it never is any different.
When I take out my Hanna checker

Using this my Po4 will be 0.05.
Never had really a high reading.
My corals are my indication too, when SPS turn a little bit light on their hand I just feed a bit more.
What I test daily is ALK and weekly No3 and K.
Cal and Mag and if I feel like it Po4 biweekly.
I do a triton test every other month just to double check my own test.
Knowing what's going on in the tank can give you a early indication if something is wrong and for that taking out the test kits.
I know where you want to go with your question as if you read 0 it's not really 0 in most cases.
That said I think we hobbyist should stop using the term "0" but rather use "to low" if that makes sense.

 

[sundog101]

How are you measuring phosphate? 0 means different things with different methods.

I'm using a Hanna checker so I'm not factoring in organic phosphates. Also the algae isn't an "outbreak", it's just in a few spots. So for a mixed reef what should I try to keep my nitrates at?

 

[Randy Holmes-Farley]

IMO, optimal levels of different nutrients will depend on what creatures you keep and wheether you have an algae problem,

In the absence of an algae problem, a reasonable recommendation for a typical mixed reef aquarium is about 0.01-0.02 ppm phosphate and maybe 0.1 to 2 ppm nitrate. With problem algae, I'd lower the levels.

 

[Diesel]

Randy, sorry if I jumped the gun.
I thought your question was pointed at my comment about "0".
Just disregards if so.

 

[Gwitness]

So what is considered not having an ulns system then?? Anything above those numbers that were stated above? Or more nitrates only? I always get confused with these terms....I have a mixed reef right now and do not want to have an ulns.....what qualifies me having an ulns and not?? nitrates are at 2 and phosphates 0.03 and I nopox dose along with weekly water changes

 

[Randy Holmes-Farley]

Randy, sorry if I jumped the gun.
I thought your question was pointed at my comment about "0".
Just disregards if so.

I did mean the OP, but no problem. :)

 

[Randy Holmes-Farley]

So what is considered not having an ulns system then?? Anything above those numbers that were stated above? Or more nitrates only? I always get confused with these terms....I have a mixed reef right now and do not want to have an ulns.....what qualifies me having an ulns and not?? nitrates are at 2 and phosphates 0.03 and I nopox dose along with weekly water changes

I don't think there's a strict definition, but I'd say any combination of nutrient levels that is beginning to starve zoox and thereby reduce the populations in corals (lightening them in color/reducing brown).

Could be very low nitrate, could be very low phosphate, or both.

OTOH, one can have very low levels of both but have adequate organic foods (as in the ocean) and not be, IMO, ULNS. :)

 

[Gwitness]

Haha makes sense and still kinda confusing!! So for example I could carbon dose and had 0 phosphates and 0 nitrates but have a lot of fish and feed them and therefore have super low nutrients but still have some nutrients from fish food and poop....therefore not being considered an ulns eventhough my numbers read 0....right?? Hahaha