Looking for feedback, Vodka / Carbon Dosing, Big Tank, Big Nitrates

[Bill1119]

Thanks again for the input!
Post 1 of 2 today

Frogger, my algae growth is not under control, but I have seen worse. It was just algae till the last month, when I had a cyano outbreak. Other than the cyano it has not been significant enough that I can manually remove it other than that on the sand or glass. I have a few tangs and a urchin that keep the algae growth short. There should be a lot more coraline algae showing on the rock.

The basic corals are reasonably healthy, the star polyps are at about 70%, and the mushrooms and leathers seem not to care other than not substantial growth.

Here is a photo of the current condition of the tank for reference.

CanReef UpLoad.jpg

[Bill1119]

Thanks for the info Simons,

Would you be willing to disclose how high your nitrates were when you were having problems?

I will do some reading on the NoPox and give it consideration.

I have a comfort level with vodka, because I had been down the road once, but I am not far enough into dosing yet that it would be a substantial problem to switch (ramp one down and one up with discretion)

I had thought about vinegar briefly but am clinging to the familiar with vodka right now.

[Bill1119]

Post 2 of 2 today...

From my research to date, it appears that risk of aggressive dosing is largely two - fold.

First if the bacteria colony is grown to fast, the "bloom" can rapidly deplete the oxygen, resulting in pH and alkalinity falling and potentially crashing the tank. Let alone the harm the can be done to the fish and corals from instability in the tank parameters.

Second, if the bacteria colony is not reduced to a reasonable size by the time the nitrates and phosphates reach the desired level, the bacteria can continue on a run away and totally eliminate all the nitrates and phosphates (this is my interpretation of reading between the lines but not specifically stated) which also has a negative effect on the tank. Articles are less forward in discussing this effect, they only state that it leads to problems with tank parameters.

My tank carries some additional risk on the second item as it has had sustained high levels of nitrates for a long time, which leads to saturation of the rock and sandbed. As the bacteria consumes the nitrate in the tank, more is released from the rocks and sand. It is possible that I could build an oversized bacteria colony, and when the saturated nitrate runs out, I could end up taking my nutrient levels down to far. Or end up with problems with tank parameters, that they are somewhat elusive on.

Based on my experience last time I was carbon dosing, I still want to take a more aggressive stance, but have more understanding of the risks. So I am on course for the following plan, increase Vodka dosing by 1.2ml per week for the first 12 weeks, then reduce to 0.5 ml increases per week.

Once I see a 50% reduction in nitrates, I will reduce the dosing by 25% and then maintain consistent dosing. I can monitor to determine if the nitrates are still falling or if need be slowly increase the dosing to begin the nitrate falling if need be.

At each 1/4 point from my initial 250ppm, I will reduce the dosing by 25% to try and scale the dosing down and not over shoot on the bottom end.

There are a few things that are on my radar for consideration, the first is that my UV sterilizer may inhibit bacteria growth, I will be shutting it down for the time being. It may even be an asset to slow down the bacteria colony on the bottom end.

The other item is to increase the oxygen saturation, I have some old skimmers around that I could put on the tank. I dont think I want to set-up ozone at this point, which is the other option to increase oxygen saturation.

I still expect this will take more than 6 months to get any substantial results, With the amount of saturated nitrate in my rock and sand. Once I achieve 125 ppm, I will increase the water change frequency to help add stability.

Cheers
Bill

[MrNaso]

I have a 500 gallon + system,mixed reef with fish,feed heavy.I have used nitra-guard bio-cubes titanium for 3 years and my Nitrates stay in the area of .30
phosphates .05 or less.I also run two large skimmers.
Great product add approx 250ml a month to replace what has been used up.

[LifeIsGreat]

I'm not an expert by any means, I probably know less than you, but have a look at some of the discussion regarding sand bed depth. Unless you regularly vacuum out that shallow bed all the way to the glass, that sand might be saturated to the point where it can't consume any more bad stuff. That may be where your high numbers are coming from.

[juanlien]

Following!this seems like a very interesting thread

[kwirky]

I tried dosing vodka and it just led to dinos and it threw everything out of whack. The bacteria consumes the nitrate in an unbalanced manner, which led to other problems.

Since you already have a fuge have you thought about bumping the lighting on it WAY up and then dosing nitrate/iron/phosphate to keep up with the macro growth? If you have high nitrates then it means your fuge is probably light and/or micro nutrient limited.

What's the light on the fuge? For a 200-ish gallon tank, if you want it to out-compete your display lights, you need lots of light over the fuge. Get yourself a 100W COB grow light ( with a cree CXB3950 3500k, used for growing/vegging the marijuanas) with a dimmer knob (important) and you should no longer be light limited. Start it at half output. You might need two of them but the nice thing is you can add another one later.

You might see more success with chaeto in the fuge. Make sure there is adequate water flow, too, in the fuge. If it's stagnant then you're not bringing nutrient rich water to the macro algae & it'll starve itself out as it's photosynthesizing. About 10cm/second of water flow through the macro algae should be adequate, with a powerhead of some sort.

Theoretically, once your light is strong enough in the fuge and if you're keeping up on iron, you'll end up nitrate limited and will need to dose it here & there to keep it above 0.0ppm.