Ideas on getting nitrates up

[Myka]

Matt, did you find this article? The article is regarding elevated nitrate, but does talk about the effects of alkalinity with nitrate and photosynthesis too.

http://www.reefedition.com/nitrate-i...reef-aquarium/

[warriorcookie]

Originally Posted by Myka

Matt, did you find this article? The article is regarding elevated nitrate, but does talk about the effects of alkalinity with nitrate and photosynthesis too.

http://www.reefedition.com/nitrate-i...reef-aquarium/

Nice find! I'll read it more thoroughly later. A quick skim, this caught my eye:

Note that this process consumes alkalinity (the H+ being produced shows this). So when nitrate is accumulating in a reef tank, alkalinity is being depleted. Production of 10 ppm of nitrate will deplete about 0.16 meq/L (0.45 dKH) of alkalinity. If this nitrate is removed by water change, that alkalinity is lost forever. If the nitrate is taken up by an organism (algae, coral, bacteria, etc.) and used, then all of that alkalinity is returned to the system (see equations below showing this fact).

Curious, when I dose nitrate and the bacteria consume it does that contribute Alkalinity to the system? I know it would be insignificant. If I was dosing an additional 1ppm a day that would equate to .045dKH per day.

In most cases where nitrate levels have been examined in relation to the growth of calcareous corals, the effects have been reasonably small, but significant. Elevated nitrate has been shown to reduce the growth of Porites compressa (at less than 0.3-0.6 ppm nitrate),16,17 but the effect is eliminated if the alkalinity is elevated as well (to 4.5 meq/L). One explanation is that the elevated nitrate drives the growth of the zooxanthellae to such an extent that it actually competes with the host for inorganic carbon (which is used both in photosynthesis and in skeletal deposition). When the alkalinity is elevated, this competition no longer deprives the host of needed carbon.17

This makes sense. The higher the nutrients the higher Alk is needed. Likewise, low nutrients generally requires low Alk. Are they suggesting coral growth and zooxanthellae overproduction (browning) happens at levels of .3 to .6ppm? Anecdotal reports 1 to 2ppm being fine... Also, 4.5meq/L is just over 12.5dKH!


Anyway, I'll spend more time with it and wrap my head around it later.

Thanks!

[warriorcookie]

Ok, tests as follows:

NO3: .2ppm
PO4: .07ppm

GFO has been off for 24 hours now.


So, yesterday I dosed 1ppm NO3, the tested levels rose yesterday and had fallen again today. Tough to say the effect its having on PO4 because I've been running GFO and only recently shut it off.

So, 24mL solution (2ppm NO3) dosed today.

[warriorcookie]

Ok, so this is interesting:

1.5ppm NO3
0.01ppm PO4

And the water is cloudy! So, as soon as the bacteria had enough NO3 they went crazy. I tested PO4 twice. First time showed as 0. Second showed as 5ppb phosphorus (.015ppm PO4).

I'll let the bacteria bloom pass, then I'll resume dosing NaNO3.

[warriorcookie]

PO4: .024ppm
NO3: Didn't get home until super late. I don't know about anybody else, but I can't get a very good read on the Salifert test without sunlight at my back. Artificial light just doesn't do it for me.


My skimmer pulled a half a cup of the nastiest crud in the last 24hours! Very thick and smelly!

Can't really comment on how things are looking as the lights were off when I left this morning and were off by the time I got home. Both anemones look deflated, but that's not necessary abnormal. Overal things are still coloring up from the bleaching. Steady improvement over the last few days.

[Myka]

Originally Posted by warriorcookie

And the water is cloudy! So, as soon as the bacteria had enough NO3 they went crazy.

Originally Posted by warriorcookie

I don't know about anybody else, but I can't get a very good read on the Salifert test without sunlight at my back. Artificial light just doesn't do it for me.

Try using a cool white fluorescent tube for checking. Warm colored bulbs make the NO3 kit impossible to read, but yeah sunlight is easiest. When the Salifert kit is used up, try the Red Sea Pro nitrate kit - it has a second vial that you match the colors to each other. I find it easier to read than Salifert when NO3 is less than 10 ppm.

[Ryanerickson]

This is interesting as I have the exact issue zero nitrate and phosphate always .03-.07 by the way Hanna is your best bet for nitrate test kit screw the color matching game.

[warriorcookie]

Originally Posted by Myka

Try using a cool white fluorescent tube for checking. Warm colored bulbs make the NO3 kit impossible to read, but yeah sunlight is easiest. When the Salifert kit is used up, try the Red Sea Pro nitrate kit - it has a second vial that you match the colors to each other. I find it easier to read than Salifert when NO3 is less than 10 ppm.

I've got a garage full of them. I'll try it this afternoon. I'll check in in both daylight and the garage and see if there's a difference.

Originally Posted by Ryanerickson

This is interesting as I have the exact issue zero nitrate and phosphate always .03-.07 by the way Hanna is your best bet for nitrate test kit screw the color matching game.

Ya, I agree but Hanna doesn't make a hand held colorimeter for Nitrate. Only Nitrite... They make a portable photometer, but it's $355 USD!

It feels so weird dosing nitrate.... I've been so proud I've had undetectable levels for the last year, but frustrated with the amount of cyano I've battled...
It makes sense. Bacteria, corals, fish, you, me all need Carbon, Nitrogen, and Phosphorus in different ratios. The ratios are different depending on the organism, but it's a triangle. My reef was deficient in Nitrogen. Some are deficient in Phosphorus or Carbon. If you feed the bacteria enough of all three they flourish. I'm pretty sure the cyano was doing so well previously because it was getting plenty of carbon and phosphate, and for nitrogen they are particularly good at "fixing" atmospheric nitrogen.

[warriorcookie]

The lights in the garage seem to make it easier to read the Salifert NO3 test.

NO3: 2.5ppm
PO4: .03ppm

Yesterday I dosed 1ppm NO3, today was none.

Seems now PO4 is the limiting nutrient. NO3 is the highest I'd like to see it. I'll stop dosing until it gets below 1ppm. Lets see how long it takes.

[Ryanerickson]

Are you running rowa or something to absorb phosphate? or at this point just relying on the nitrate to help keep phosphate low .