Coral issues due to Nutrients?

[arking_mark]

Well, hard to say what caused your issues.

Seems to be the trend with my tank. Early going is all about finding balance and stability. This is my 5th DT in over 25 years, and the last one was a more simple AIO.

 

[Lasse]

IMO, suggesting that nitrate will prevent hydrogen sulfide issues (or conversely, that zero nitrate will cause them) is exactly like claiming that higher alkalinity will prevent low pH or that low alkalinity causes it.

I do not get this
Sincerely Lasse

 

[schuby]

IMO, suggesting that nitrate will prevent hydrogen sulfide issues (or conversely, that zero nitrate will cause them) is exactly like claiming that higher alkalinity will prevent low pH or that low alkalinity causes it.

I'm unable to follow your logic that the removal of an inhibitor leads to causation, when the process being inhibited is not always occurring. Here's a non-chemistry equivalent of my perception of your statement, whose logic I also can't accept:

Humans can prevent forest fires (or conversely, the removal of humans will cause them).

I'm fairly sure that @Lasse did not infer that zero nitrate will cause hydrogen sulfide, only that some Nitrate (not high Nitrate) will likely prevent the creation of hydrogen sulfide by anaerobic bacteria in the sandbed of a reef tank. For the safety of fellow reefers (most on this site don't have the chemical understanding of yourself and Lasse), he recommended keeping some Nitrate rather than zero. 1-2 ppm of Nitrate is "some" for both noobs and most of the rest of us as our test-kits don't clearly discern values less than 1.

If a reefer doesn't have a sandbed or has no anaerobic bacteria in his sandbed due to hardly any sand, then the likelihood of the creation of hydrogen sulfide seems to be practically zero. Similarly, humans can prevent some forest fires by not tossing cigarette butts out their car-windows and by completely putting out their camp-fires. The removal of Nitrate won't always create sulfide gas and the removal of humans won't always cause a forest fire to start.

 

[Randy Holmes-Farley]

I'm unable to follow your logic that the removal of an inhibitor leads to causation, when the process being inhibited is not always occurring. Here's a non-chemistry equivalent of my perception of your statement, whose logic I also can't accept:

Humans can prevent forest fires (or conversely, the removal of humans will cause them).

I'm fairly sure that @Lasse did not infer that zero nitrate will cause hydrogen sulfide, only that some Nitrate (not high Nitrate) will likely prevent the creation of hydrogen sulfide by anaerobic bacteria in the sandbed of a reef tank. For the safety of fellow reefers (most on this site don't have the chemical understanding of yourself and Lasse), he recommended keeping some Nitrate rather than zero. 1-2 ppm of Nitrate is "some" for both noobs and most of the rest of us as our test-kits don't clearly discern values less than 1.

If a reefer doesn't have a sandbed or has no anaerobic bacteria in his sandbed due to hardly any sand, then the likelihood of the creation of hydrogen sulfide seems to be practically zero. Similarly, humans can prevent some forest fires by not tossing cigarette butts out their car-windows and by completely putting out their camp-fires. The removal of Nitrate won't always create sulfide gas and the removal of humans won't always cause a forest fire to start.

I think perhaps some folks are missing my point.

I agree that there is an inhibitory effect of nitrate on hydrogen sulfide production.

There is also, obviously, an inhibitory effect of O2 on hydrogen sulfide production.

Generally, the inhibitory effect of 5 ppm nitrate will be less than the inhibitory effect of near saturation O2 because there are simply more moles of inhibitory molecules in saturation O2 than in 5 ppm nitrate, both of which MUST be consumed before H2S is produced in significant quantities.

No one is claiming that O2 in the water will prevent hydrogen sulfide production (say, deep in sand contaminated with organics), and so it seems to stretch logic to claim that 5 ppm nitrate will prevent it.

Yes, the nitrate helps a bit. Might there be a scenario where 5 ppm nitrate will be just enough inhibition to prevent H2S production while the O2 was not? Sure.

Might there be a scenario where even 100 ppm nitrate is not enough inhibition? Sure. Bury a dead fish in sand and let's see.

Is the inhibitory effect of, say, 2 ppm nitrate, significant in that it will prevent problems with sand in a reasonable number of reef aquaria?

That is a debatable point that I do not know the answer to , and would assert that others do not either. I personally do not think it is particularly important, but cannot prove it.

 

[Randy Holmes-Farley]

I do not get this
Sincerely Lasse

I think it is actually a perfect analogy, but if it does not convince anyone, let's drop that approach.

 

[Lasse]

I use 2 ppm as breakpoint because there is studies that indicate that it seems to be enough in order to depress hydrogen sulphide formation in the upper sediments of freshwater lakes. There is a very good report here in Sweden of this but unfortunately - its only in Swedish. It is about vertical migration of some cyanobacteria (nitrogen fixators) that migrate down to the bottom during night in order to pick up phosphorous from the sediment. They found that in lakes with NO3 concentrations around 2 ppm - this type of cyanobacteria did not exist - instead the population of phytoplankton was of non migration type. They knit this into a hypothesis that the migration type was lacking because there was no phosphorous release from the sediment because there was nor enough production of hydrogen sulphide that´s is necessary in order to break metal- phosphorous bound (mostly iron bound phosphate)

Large scale test have later on shown that production of this type of migrating cyanobacteria disappear in water bodies receiving nitrate from sewage plants in the same order of concentration but the method was abandoned because researchers were more concerned about nitrogen fertilization of the Baltic Sea compared to local cyanobacteria problems.

Its mostly from this study - I get my 2 ppm.

There is also studies (and a developed methods) using nitrate in sewage system in order to depress hydrogen sulphide production - but in these cases (highly biological loaded system) the proposed concentration in sewage pipes is around 30 to 40 ppm NO3

No one is claiming that O2 in the water will prevent hydrogen sulfide production (say, deep in sand contaminated with organics), and so it seems to stretch logic to claim that 5 ppm nitrate will prevent it.

Yes, the nitrate helps a bit. Might there be a scenario where 5 ppm nitrate will be just enough inhibition to prevent H2S production while the O2 was not? Sure.

I will say it will during certain situations. Let us say that we have 7 ppm O2 in the water and 5 ppm NO3. If we do not have any bacteria in the sandbed - can we agree that both the O2 concentration and NO3 concentration will penetrate all the way down to the bottom of the sand bed (in the pore water). There is no consumption of either the O2 or NO3

Now we ad some organic matter to the sandbed - it means bacteria will enter our system. Oxygen is the most effective electron acceptor, therefore will it be consumed in the sandbed. IME it is not normally oxygen that is the limited factor for heterotopic bacteria growth - it is normally lack of DOC (dissolve organic carbon) that limit bacteria growth, hence oxygen consumption. But we have after some years an old mature sandbed with enough organic that oxygen will be limited factor further down in the sandbed. (By the way - I have seen - even in old mature system that the sand have some oxygen even down to 4-5 cm).

Available oxygen will have these bacteria grow rather fast and when its gone - they switch (the same bacteria) to use NO3 instead. But let us say - the oxygen is consumed by the bacteria at a depth of 3 cm (just an example). The NO3 has not been used - its still there. Now the bacteria start to use the NO3 instead of O2. (if there is no NO3 in the water - the hydrogen sulphide producer will start directly!) NO3 much less effective as an electron acceptor (less energy) - the bacteria growth slow down. The NO3 will serve as a new resource. Let us say now that the water above the sediment (and down X mm) will serve as an reserve of both O2 and NO3 . If all oxygen is consumed in the porewater - new oxygen will come down from the water column - its the same with the NO3 and the NO3 will penetrate deeper and consumed more slowly because is nor consumed as long as there is oxygen in the porewater.

Let us say that we have no NO3 in the water - The oxygen will be consumed and when its consumed - the hydrogen sulphide producers can start directly. Hydrogen sulphide is a gas and it will start to rise up from the sand. However - when it meet oxygen - it will be oxidized to sulfur dioxide - it means it will consume oxygen from the water. This all means that it can be a rather fast event if you get low in oxygen in some places in the aquarium and with some NO3 in the water you will slow down the process. I think this is rather important as soon as we start to try manipulate the system trough adding DOC (like vodka and so on)

IMO - to use NO3 in the water column is the same as using safety belts. You should not crash - but if you do - it save something.

Sincerely Lasse

 

[arking_mark]

...back on topic...

So I now have NO3 at 5ppm and PO4 bouncing off 0. Seems like heavier feeding is keeping everything off 00s . I'll continue to monitor, but I don't think I have a nutrient problem at this time.

I'm guessing that if I can maintain stability I should see some improvements in coral.

I attribute the lowering nitrate to my refugium starting to produce...ChaetoGro may have helped.

However, I still believe my issue may be the lighting...and had little to do with nutrients.

 

[ReefBeta]

Your tank's journey looked very similar to mine, chemically, start with 20ppm NO3, <0.03 ppm PO4, refugium not doing well, WD Tenius growing well, Kung pow died. But I solved it a bit differently.

For the chemistry part, my believe was that phosphate had become the limiting factor for nirate to be consumed, so it's not a low/high nutrient problem, but a nutrient imbalance problem. With that, my solution was to dose PO4 directly to fix the imbalance. So I dosed about 0.01 ppm phosphate daily for about a month to finally managed to keep it stabilized between 0.05~0.1ppm. After that, I stopped dosing and phosphate level remain stable at that range. Feeding was not changed much during that period. Nitrate has been at 20ppm the whole time. It didn't drop back down until I restarted the algae reactor with some new chaeto to get it working again. But after all that, the corals have not show too much difference. The biggest help from this change is dino are gone for good. Before that, if any frags showed any tiny trouble at all, dino will quickly get on it, and it's basically doomed. Now without dino, the troubled frags have chance to bounce back. But just for the dino reason to keep phosphate up is worth it IMO.

The bigger improvement is light, same as your thought. Even though the peak PAR in my tank is only 300 PAR, the corals had problem are mostly under the center of the radion. So usually the solution that help is to take them off and put them in a dimmer area, around 200 PAR. I managed to save several frags with that, including a pearlbeery, honeycomb, shade of all, and purple bonsai. Eventually I lowered my light intensity by 10% overall. From what others said, 300 PAR should not be too high for acropora to handle, and there are many other frags doing pretty well sitting just couple inches from the problem spot. So maybe it's not a problem with the system at all. It's just the adaptation for each coral is different. When you see a coral having problem, try move it, usually to lower light area, to see how it react.

 

[Lasse]

FYI

Experiment and discussion about calcification rate in my Aquarium

A description of my aquarium. I use Core7 Triton method in order to maintain most of my parameters The aquarium is around 310 L water Heavy stocked with both hard and soft corals and 5 clams 40+ fish in small and middle sized fish The filtration A reversed deep sand bed Refugium (the DSB is in...

www.reef2reef.com

Sincerely Lasse

 

[arking_mark]

Your tank's journey looked very similar to mine, chemically, start with 20ppm NO3, <0.03 ppm PO4, refugium not doing well, WD Tenius growing well, Kung pow died. But I solved it a bit differently.

For the chemistry part, my believe was that phosphate had become the limiting factor for nirate to be consumed, so it's not a low/high nutrient problem, but a nutrient imbalance problem. With that, my solution was to dose PO4 directly to fix the imbalance. So I dosed about 0.01 ppm phosphate daily for about a month to finally managed to keep it stabilized between 0.05~0.1ppm. After that, I stopped dosing and phosphate level remain stable at that range. Feeding was not changed much during that period. Nitrate has been at 20ppm the whole time. It didn't drop back down until I restarted the algae reactor with some new chaeto to get it working again. But after all that, the corals have not show too much difference. The biggest help from this change is dino are gone for good. Before that, if any frags showed any tiny trouble at all, dino will quickly get on it, and it's basically doomed. Now without dino, the troubled frags have chance to bounce back. But just for the dino reason to keep phosphate up is worth it IMO.

The bigger improvement is light, same as your thought. Even though the peak PAR in my tank is only 300 PAR, the corals had problem are mostly under the center of the radion. So usually the solution that help is to take them off and put them in a dimmer area, around 200 PAR. I managed to save several frags with that, including a pearlbeery, honeycomb, shade of all, and purple bonsai. Eventually I lowered my light intensity by 10% overall. From what others said, 300 PAR should not be too high for acropora to handle, and there are many other frags doing pretty well sitting just couple inches from the problem spot. So maybe it's not a problem with the system at all. It's just the adaptation for each coral is different. When you see a coral having problem, try move it, usually to lower light area, to see how it react.

Interestingly enough, new corals added to tank typically bleach, brown out, or don't thrive.

Corals I transferred from my old tank did mostly fine accept a kung pow that browned and then died.

There are only 4 corals I transferred that I care about: Jellybean Chalice, Jawbreaker, Godspawn Bounce, and Walt Disney. They are doing well...so I'm not really willing to make to many changes at the moment.

The new tank is using the same kessil lighting with UV band on equal to intensity. The reason I bring this up is I suspect the UV band provided by kessil may be the issue with new coral not used to that lighting.