Dosing sugar to reduce NO3 and PO4 in Saltwater Aquarium
In a recent post we talked about how to reduce NO3 and PO4 by dosing vodka (see Dosing Vodka to reduce NO3 and PO4…). Today, we will have a look at an other technique, very similar to vodka dosing, where sugar is used to reduce NO3 and PO4.
Why sugar?
Phosphate and nitrate are the two main nutrient reduced when adding organic carbon. Basically, dosing any other kinds of any organic carbon would give you the same results.
People have also experimented this with vinegar, vodka, etc (all of which are organic). Sugar is cheap and easy to dose.
How does it reduce NO3 and PO4?
I am not a chemist so won’t go deep into the scientific area of this. To make a long story short, if you add something carbon based, such as sugar (or vodka), the bacteria will feed on it and their number will increase. The bacteria will be consuming more and more NO3 and PO4 to build their cells. The excess bacteria in turn will be skimmed out, resulting in lowering your NO3 and PO4 reading.
Before to go any further, I strongly recommend you read the entire post and also the link provided at the end. You should also know that many aquarist don’t want to use this technique because they are still unsure about the longterm effect of dosing carbon. An other down side of dosing sugar it that it is not as well documented as it is for vodka dosing. However, I have been told this technique is quite popular in Germany but could not find much information about it. Sugar users usually note a dramatic decrese in NO3 and PO4 (from over 50ppm to less than 5ppm in some case). Most of the people that have tried it, swear by it.
The Skimmer
A good skimmer is a key requirement for this method. Cultivating bacteria to lower NO3 and PO4 is one thing but you also need to remove those bacteria from your system. If you keep the bacteria in your system, they will eventually set those nutrients free when they die. You can’t rely on water changes for that so make sure you have a good skimmer! The other reason for using a skimmer is gas exchange. The increased bacterial biomass will decrease your dissolved O2 levels which can cause stress (or death) to the reef inhabitant.
Dosing Instructions
While vodka dosing is well documented on the Internet, I found nothing clear about how to use sugar. This is actually why I now dose vodka instead of sugar. For that reason, I can’t provide a detailed dosing regime here. Instead, I will simply quote some dosing regimes found on the many forums I have read to come up with this post. This way you’ll be able to make your own conclusion and to try it if you want to.
…you better be safe than sorry so start with small dose and adjust…
Keep in mind that if you start out with too much, you’ll crash the tank.
Too much sugar will cloud your tank… …in fact the only time my water got cloudy was when it got very high and I added a little more than I should of.
three good reasons to start with small doses
1 tsp (Teaspoon) of sugar is equal to 10 ml of vodka (80 proof)
If this is right, 1/10 tsp per 25 gallon would be a good starting dose (this is what is recommended for vodka dosing). Then, I assume we can simply follow the same dosing instruction as vodka dosing.
I dose about 2 tsp per day in 500+ gal of tank water and it is dosed 24/7 by a dosing pump.
2 tps in 500 gallon = 1/10 tbs in 25. Again, the dosage is the same.
I’ve added as much as 6 heaping tsp at once to my 600 gallon system, just to give you an idea. I’m not sure what the specific guidelines are, or if they even exist…
This is 1/4 tps per 25g
I found a forum and they were discussing the benefits of adding 1/8 teaspoon of sugar per every 70 gals of tank water, in order to reduce nitrates…
Unless I am wrong, this would be close to 0.5/10 tbs per 25 gallon.
If you still have the 120, you could probably start at 1/2 tsp or so with no problems.
Here again, 1/10 tbs per 25 gallon
Assuming 1 tsp (Teaspoon) of sugar is equal to 10 ml of vodka (80 proof), people who use sugar usually follow the same quantities as recommended for vodka dosing. If that’s true, I would say we can use the same dosing routine. see: Dosing vodka to reduce NO3 and PO4 in Saltwater Aquarium.
If any of you tried this technique, please let us know your conclusions! Thx.
Source
Reef Central – Nitrate Reduction 101 with sugar!!!
Reefkeeping.com – Sandbeds and vodka, part 3
Aquaria Canada – SUGAR SUGAR SUGAR…Have you tried dosing it?
The Reef Tank – Dosing sugar???????
Reef Central – dosing vodka to bring down N and P
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Great article. I did not realize that sugar would reduce NO3 and PO4 in fish tanks. I have always tried the products in the store but this seems like a much better and cheaper way.
Hello!
I haven’t try the sugar idea yet. I have been dosing vodka in my 25 gallon reef tank for the last 3 weeks now (same idea as sugar). It works well. My No3 and Po4 use to be close to 1 and they are now undetectable using salifert test kit.