Raising nitrate and phosphate without growing algae

[Dan Reef]

I had a refuge full of macros and dosing Triton. With the time GHA started to grow everywhere. I'm not sure if my PO4 Hanna test is accurate but it was showing around 0.15ppm. Undetectable nitrates, however. Even adding GFO didn't make any difference and this is the reason I suspect the test is not accurate for some reason.

I started to suspect my tank was running very low on nutrients, even PO4 despite what the test was showing.

So I decided to add NO3. And GHA simply exploded.

I then decided to return to my old simple method which was just skimmer, some bioballs and a little ZeoStart. In 1 month the algae died and the tank is clean again.. unfortunately I lost some corals including a nice and large milepora green. NO3 has raised to 5ppm. Not sure about PO4, need to get a different test to confirm if Hanna is accurate.

My opinion is that if you dose NO3 with GHA or dynos in excess it will only make it worst. Now that my tank is clean I'm ready to try refugium again but with much more careful and adding NO3 and/ or PO4 before GHA takes place.

With refugium been the trend again but with more filter methods and better lights in comparison to the past I guess many reefers are having issues similar to mine and correct the issue in time maybe the key to avoid algae/ dynos/ cyanos.

 

[scottrotton]

I think the fact my think is not balanced is the biggest issue, i will keep dosing to bring my phosphates down, once they are in balance or near i will see how the tank progresses, hopefully i wont need to keep dosing. Think will do a water change and manually remove any algae. Its definitely been getting worse as i've been dosing nitrate this week and i still have no nitrate reading at all and 3ppb Phos.

If it starts to take hold again i may try and run something i've been thinking about for a while but ive never seen anyone attempt. if you know of anyone that does this please let me know

1. 3 day blackout to get algae on back foot
2. 2 filter methods, 8 hours turf scrubber with 16 hours of refugium lighting the cheato.
3. That way the main display nuisance algae is always competing against macro algae rather than reverse cycle where for at least 8 hours per day nuisance algae has chance to take foothold without competition. I used to run my fuge for 24 hours but kept dying hence the alternative methods.
4. Continue to dose nitrates and hope macro absorbs instead of micro

In combination to the i will get a sea cucumber to help with what other patches may pop up whilst it settles. I will document to see if this works or not, in theory it should work well but who knows :)

 

[Lasse]

@scottrotton reading 3 ppb with Hanna is below its accuracy. You can have zero in P. I´m still rather convinced that you dealing with a low (or zero) nutrient problem. But I can be wrong. It has happen before.

@biophilia and @taricha Interesting thoughts. However when you talk about 0.5 ppm and wanted 1 - 2 ppm - do you mean Si or SiO2? Because I use Sera Siporax in anaerobic conditions - my Si concentration run up to more than 20 ppm (Si - Triton test) and test results show that it was on its rise (It corresponds to nearly 43 ppm as SiO2). After changing of the construction of my DSB (taking out the siporax) my Si concentration went down to around 0.3 ppm as Si (around 0.6 ppm as SiO2)

I did not have any problems with diatoms even when I read 20 ppm as Si but I got precipitate of Si on my windows!

I´ll put this trick inside my toolbox for further tests :) There is one more good things with having Si concentrations above 0.1 ppm - it will make your sponges (and some other invertebrates) to thrive. @Sallstrom from the Maritim Museum of Gothenburg always nag about the importance of the sponge loop in order to have stability

@Daniel Decourt I was rather convinced that it was not GHA in this case. GHA can strip the water for both N and P but in that case I´m with you not to add NO3 or PO4. I am rather sure that this brown dust normally not is Dino but can´t be sure.

Cyanobacteria exist in many different forms and species - not only in the form of the red or green mats.

Sincerely Lasse

 

[taricha]

Here's what silica looks like in my tank over a 10 day period of relative stability.
@biophilia @Lasse
I'll talk about Silica in the form SiO2, because that's the form that the dosing product SpongExcel uses in its instructions, and also the form that the Hanna Low Range Silica meter reports results in.

The low numbers in the zig-zag are the tested values, and the high numbers are calculated after daily dosings. Si is rapidly consumed in my system, but I think in systems without so many sponges, Si can stay around longer.
(I picked target around 2.0ppm SiO2, because it's in the ballpark of NSW levels, it's high enough not to deplete totally in a day or two, and 2.0ppm is the max my meter will read:) )
Lasse, that's crazy about siporax, I have had low level sponge growth for years in my tank before dosing silica, which I after the fact attribute to having a half liter of beach sand mixed in the sandbed.

 

[biophilia]

@taricha Thanks for the graph. I'm going to up my current dose to every other day and observe carefully. I wouldn't be surprised if my system pulls SiO2 out of the water column that fast. About 60% of the rock I can see in the caves below my aquascape is completely covered in sponge so I know that the biomass is pretty substantial. I have noticed that there seems to be a bloom in sponge growth only in the first few days after my weekly dose. I'll bite the bullet and pick up a SiO2 test kit...

 

[taricha]

About 60% of the rock I can see in the caves below my aquascape is completely covered in sponge so I know that the biomass is pretty substantial. I have noticed that there seems to be a bloom in sponge growth only in the first few days after my weekly dose. I'll bite the bullet and pick up a SiO2 test kit...

Based on visible sponge coverage of rocks, your rocks sound like the underside of mine, and may have Si consumption similar as well.
Just FYI, several people have been unable to detect anything (even with known Si source) with salifert Si kit.

 

[Lasse]

One very interesting thing that´s happen in my aquaria was that my sponges - that have start grow very well - just disappeared from my aquarium when my Si levels rise a lot. I have no idea if it connected with to high Si levels or something else. Now - when my Si levels (as Si) have turned down to 0.3 ppm - I have got some of these sponges back again. There has been some small species of sponges in my sump and in my wavemakers all the time but the "macro" types just was not there. Please see my latest post in my build thread

Sincerely Lasse

 

[biophilia]

Based on visible sponge coverage of rocks, your rocks sound like the underside of mine, and may have Si consumption similar as well.
Just FYI, several people have been unable to detect anything (even with known Si source) with salifert Si kit.

Thanks for the heads up. I'll avoid it!