Skimmerless Vodka Dosing?

[vikinglord13]

I've been doing some reading on RC on vodka dosing and a common theme I hear is to make sure one does it with a good skimmer because of the excess bacteria growth.

My question is if anyone has dosed, or does dose, vodka and not use a skimmer? What are your results? Does it really matter if the bacteria is caught by the mechanical filtration? I have a friend who does and he doesn't seem to have any nitrate/phosphate issues, better than myself anyways and I've never dosed before.

[CStrickland]

It would be an easier question to answer if we really knew how carbon (vodka is only one source) dosing works, and skimming too tbh. Basically, people add carbon to their tanks by dosing vodka or vinegar or nopox or hooking up a Biopellet reactor, their skimmate gets gnarly looking, and their levels go down. So, it seeeems like the skimmer is removing something.

If so, is the carbon roiding up the bac population and the skimmer removing bacteria that have built their bodies from the nutrients we want out? Maybe, but if bacteria are flying around in the water that much, uv would work better and large waterchanges would have more impact. Or is the bacteria staying attached to surfaces and being roided up, then pooping a lot, which the skimmer removes? Maybe, especially the ones that don't need oxygen to process nitrates, but that is hard to get your head around.

There's a few people who use biopellets without skimmers. It's carbon too, but there's a little more to it. Most recommend a skimmer. Like, once you try carbon dosing with a skimmer and see what nasty stuff comes out of your tank, it's hard to imagine leaving it in there. There's so much we don't understand about it, it's hard to say that what works for your friend will work for you.

If you're having nitrate and phos issues, honestly the first step is buying a decent skimmer. Theres no downside if you can scrape together a couple hundred bucks, and you are much less likely to screw up your tank.

[vikinglord13]

Thanks for the input, I always enjoy your comments.

My main problem is cash, that's why I was looking at vodka dosing, it's so much cheaper. Granted, my tank is only a 29G biocube.

My nitrates have been much worse before and they haven't really gone up these past couple months. I'm actually find it puzzling. I'm curious if the bacteria currently in my tank are at some sort of plateau where they just keep my nitrates where they are.

[CStrickland]

Thanks!
Maybe instead of a plateau of just nitrates, it's the balance. Like, the amount you're feeding is adding X amount of nitrates, phos, carbon, and fairy dust; but your bacteria are using up something before they can clear the nitrates? And without the fairy dust they get log jammed on nitrates.

As a cheap person, I highly recommend vacuuming your sand if it's less than 3-4". I've had great luck with it as part of my waterchange schedule. I use a little powerhead to blow all the crap out of the rocks, and then a gravel vac on my sand. This way the water that I take out for a change is super dirty. I think that by getting all that poo out before it rots and dirties the water, I'm giving my bac a head start to work on the rest of the nutrients. And since I'm changing water anyway, it makes sense to be as efficient as I can with it.

[vikinglord13]

+1

I vacuum my substrate before every water change. I like to take my turkey baster and blow water into it, then siphon the crud out from the sand when I do my WC.

[gallegos]

Don't vodka dose without a skimmer. This is what happens. Bacteria population explodes with the excess food, if they are not removed from the tank via skimmer, they die off and the nitrates and phosphates they consumed are released back into the tank and the bacteria is broken down into phosphates and nitrates as well so adding to the problem

[vikinglord13]

Which makes sense. I just don't understand why my friend hasn't had any issues.

[Raintree]

your friend probably doesn't need to be carbon dosing in the first place then if they carbon dose without a skimmer. There is no point in carbon dosing without a way to export the bacteria

[CStrickland]

one of the main benefits of carbon is a boost to facultative bacteria that convert nitrate into a gas that then floats away out of the aquarium. That function does not rely on a skimmer, they stay right where they are gobbling up the nitrates and farting them out of the tank.

But, carbon is used for other things too. Like, it's the basic building block of life. I'd be worried that other processes would increase and generate stuff that ought to be removed. The skimmer concentrates and isolates a particular type of dissolved waste, and perhaps other crud and floc that comes along for the ride. If other carbon gobbling organisms besides the facultative denitrifiers are producing an excess of that waste, it will accumulate over time. And if carbon use is stopped their population will adjust and the ones that don't get cannibalized will foul the water.

Also, other processes that carbon boosts may use up oxygen that fish need. You hear people say that skimmers "oxygenate the water" but I think that it isn't so much the bubbles that it adds. IMO skimming out their food (dissolved organics) keeps that bioload lower, leaving more O2 behind. There's not really a good cheap test for O2 levels, and a lack of O2 crashes the whole tank because it's like a snowball effect from the first fish loss.

The DOC's and other productions of bacteria, as well as some dead bacteria, make the water dirty. We don't have a test for how dirty the water is, just parts of the picture by reading inorganic phos and nitrates. Since the nitrates can be off gassed, and the phos can be adsorbed into calcium structures like rock for a long time before the rock gets full and the phos-leaching nightmare begins, your friend might be cruising for a bruising with this method. Or they might have figured out just the right balance for their tank. But it's risky, hence all the advice to run a skimmer.

[Raintree]

while aerobic denitrification does happen in microbes, i have never heard of that being used in reef tanks as a reliable method of reducing nitrate. There are far easier and more reliable ways of reducing the nitrates. I just don't really see the sense in carbon dosing without a skimmer for most reefers (unless you're trying to grow bacteria as coral/sponge food in a NPS tank or something like that.. and even then i'm not sure that carbon dosing is really a great idea without a skimmer).

[CStrickland]

Originally Posted by Raintree

while aerobic denitrification does happen in microbes, i have never heard of that being used in reef tanks as a reliable method of reducing nitrate. There are far easier and more reliable ways of reducing the nitrates.

No I'm talking about anaerobic denitrification by facultative heterotrophic bacteria. What methods are you thinking of?

[BrianKC]

After seeing how my skimmate changed when I started dosing (lots more, and lots more disgusting) I would definitely not recommend doing it without a skimmer.


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[vikinglord13]

Thanks a bunch guys. For now I just won't dose carbon since my nitrates haven't really gone up over the past few months (Jan. - May). I've also been consistently behind on my water changes so I'm not too worried.