Leftover Nutrients

[sundog101]

In reef tanks we want to add things that outcompete algae for resources like nitrate and phosphate. However 0 nutrients is not the best thing for a tank. Some nutrients should be leftover. But... the ATS/biopellets/algae reactor can't be totally out competing algae if nutrients are leftover. It can take up the bulk of the N and P, but what stops algae from using the small amount that's not taken up? IME, algae takes up the leftovers, leaving none for the corals.

P.S. sorry for another algae/nutrient thread. I feel like all my questions have been about nutrients

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure I understand the question. Any method of nutrient export can be scaled to be appropriate and not overkill.

But green hair algae growth can generally be reduced substantially by nutrients low enough without starving corals. When nutrients are low algae has a much harder time getting all it wants.

That's why adding nutrients into the ocean generally results in excessive algae growth.

 

[sde1500]

I don't think there is a question. At least, thats my guess based on lack of question marks haha. I think a good CUC, paired with a good nutrient export system, will make up for leaving some nutrients in the water as well.

 

[sundog101]

My problem is that my nutrients are undetectable and I believe I'm starving out the corals. However, when I try to raise NO3 and PO4, I only get algae. No detectable nutrients. Its like algae in the DT takes up the few extra nutrients that I'm trying to have available for the corals.

But green hair algae growth can generally be reduced substantially by nutrients low enough without starving corals.

I don't know why this has been so difficult in my tank.

 

[saltyfilmfolks]

My problem is that my nutrients are undetectable and I believe I'm starving out the corals. However, when I try to raise NO3 and PO4, I only get algae. No detectable nutrients. Its like algae in the DT takes up the few extra nutrients that I'm trying to have available for the corals.


I don't know why this has been so difficult in my tank.

May I ask, how do most of your corals look? I know a couple have failed.

Is your skimmer too big?
Have you considered dosing aminos?
How much light do you have?
Is your ats still on a very long schedule?

the ATS/biopellets/algae reactor can't be totally out competing algae

This seems like overkill.

At a point your going to get algae as we've seen in other high nutrient tanks, and the solution in most every one is good cuc choices and manual removal. Honestly I hit the tank with the toothbrush once a month maybe and do water changes. for the most part that's really about it. I clean the glass once or twice a week depending where the nutrints are and what Im feeding.

Personally I have lowered my nutrints to the point the zoas almost died and still had alges. So, for me, I rather take out a little algae once in a great while than watch the coral die.
And fwiw, IMO IME, If the nutrints are low and the corals healthy, manual or cuc removal is the answer, then the nuisance algae is easier to kill and remove.

 

[Cory]

Even if your test reads 0 the corals still get that bump of nutrients from bacterial decomposition just as the algae do. So i wouldnt worry about 0s.

If the corals look bad id check all your other parameters first and increase flow.

 

[sundog101]

May I ask, how do most of your corals look? I know a couple have failed.

Is your skimmer too big?
Have you considered dosing aminos?
How much light do you have?
Is your ats still on a very long schedule?

Yes a couple of sps pieces have bleached out. Lps are lighter in color and softies have kind of shrunk. I think most are halfway ok (at least not dying), but I'm not getting much growth.

I would say my skimmer is probably on the larger side for the bioload that I have. It's a Reef Octopus Classic 150 INT. Tank is 90 gallons with 40 gallon sump. Currently have only 3 medium sized fish.

I've actually been dosing acropower for the past couple months

Two Kessil a360s at 45% max intensity. 4 hrs a day max, 6 hrs ramping up and down, 4 hrs low power (5% or less; early morning and late evening), total photoperiod- 14 hrs

ATS is on 12 hrs a day

This seems like overkill.

That was just an example . I have the ATS and protein skimmer for filtration.

 

[saltyfilmfolks]

I would turn off the ats. If there's not enough food for corals why feed that algae.
Skim dry.

 

[Cory]

Once my montipora bleached. I decided id dose 5ml of vodka in 20 gallons its in. Tank got covered in snot bacterial slime. Long strings of it in the tank. In the next week, the montipora regained its color! I believe it ate the bacteria.

 

[BlueCursor]

Different living things have different uptake efficiencies. Diatoms cannot update PO4 as well as phyto, so even though you may have PO4 diatoms may not grow while phyto does. It's the same with algae. They are not as efficient as using PO4 as corals, phyto, bacteria, etc. Keep things too low for bad algae, high enough for good things.

 

[mcarroll]

My problem is that my nutrients are undetectable and I believe I'm starving out the corals. However, when I try to raise NO3 and PO4, I only get algae. No detectable nutrients. Its like algae in the DT takes up the few extra nutrients that I'm trying to have available for the corals.


I don't know why this has been so difficult in my tank.

Feeding Is Better
From the coral's perspective, feeding your corals particulate food is better than dosing dissolved nutrients.
(click the "coral" tag on my blog for some interesting links on the topic)

Dissolved nutrient additions are great for correcting a short term deficit, but can have side-effects in the longer term.

Your nutrient adjustments may also have been too large and/or too quick.

BTW: An algae bloom is a pretty natural (and healthy) side effect of a nutrient spike....it's the beginning of a not-mini-cycle, really. New tank syndrome, but with a bigger nutrient load.

Not Starvation (Maybe)
Bleaching can be caused by a number of things, including no single thing/a combination of unrelated stresses. But it's not uncommon for P-starvation + a lighting change (or significant flow or other change) to make the situation ripe for bleaching.

Even so, I'm guessing from your description of how things go when you dose liquid nutrients that there's not much of a deficit of dissolved nutrients in your case even though tests may indicate so. A healthy growth of algae implies a cycling of P and N going on, even if 100% of it is tied up.

If PO4 really tests at zero persistently, then in spite of the algae I would still consider making a regular dose of PO4. Do what you have to in order to make your dose small enough that it doesn't make the algae go out of control. (Forget about targeting any numbers on your test kit though since your algae appear to be at least as sensitive.)

I've actually been dosing acropower for the past couple months

N+C....I wouldn't recommend this going forward due to the algae situation.

Instead try KNO3 or one of the commercial nitrogen supplements like Flourish or NeoNitro for adding N and NeoPhos (etc) for adding P.

 

[sundog101]

Will do!

 

[sundog101]

Alright so in the past month I've increased feeding and added two more fish. I also took my ATS down and now have just the skimmer and filter socks. However N and P are still zero . I've noticed more algae in the tank, but I think the corals look a little better.

I just don't understand where the nutrients are going. Could they be sucked up by algae right away or taken up by anaerobic bacteria?

I think I'll stay on this path and may look direct addition of N and P.

 

[saltyfilmfolks]

Alright so in the past month I've increased feeding and added two more fish. I also took my ATS down and now have just the skimmer and filter socks. However N and P are still zero . I've noticed more algae in the tank, but I think the corals look a little better.

I just don't understand where the nutrients are going. Could they be sucked up by algae right away or taken up by anaerobic bacteria?

I think I'll stay on this path and may look direct addition of N and P.

Two of my tanks process nutints like no tomorrow. On is my coral qt with no skimmer and the other is my little cube with not a great skimmer. So yea. It may just be hungry a lot.

 

[Deniss]

I would dose mate. I had high N and P which got me into hair algae. The corals were doing fine, and i thought a little bit of algae here and there is "normal".
Nature can't be perfect...but o man...it grew, and it grew in less than a week or 2 my tank was covered too a point i coudn't even see some zoa frags anymore.

So i went with a chaeto reactor, that thing sucked them nutrients up like there was no tommorrow! At first i literally saw the chaeto grow by day...now it stopped. So i decided to check parameters,
N And P 0. Now that my tank is algae free, i just coudn't get the N and P up, even setting my reactor to lowest intensity. (Don't want to take it off as it keeps my ph stable during night).

I bought myself a P and N bottle because i got tired to not being able to rise them by heavier feeding. Now i got my nitrates at 5 but my Phosphates still at 0, i'm slowly adding more dose as it might be sucked up by my live rock.
For now, this looks like the best solution for me. As i had a feeling some zoa's were starving, colors looked mixed up...but i'm not sure if it was due them being covered by algae or low nutrients.