CAUTION using vinegar

This post is to caution you if you are adding vinegar, acetic acid, to your aquarium such as using DIY Ca and Mg.  Acetate is an organic carbon source that bacteria will use to multiply out of control resulting in a bloom that can remove all the oxygen and suffocate fish and other animals.

Today, I added a cup full of calcium acetate to the aquarium.  Within the hour, I noticed that the water became slightly cloudy.  By the end of the day, it was even more turbid.  This happened before when I added magnesium acetate but it cleared up in 24 hours.  But this time, it was much worse and fish, shrimp, and snails were all at the surface gasping for air.  I immediately knew that the bloom had removed almost all of the oxygen so I quickly grabbed an air pump and started to aerate full blast. One of the rasboras was listless so I netted her out and tried to revive her in another tank but it was too late.  She died.

After emptying half the water.

I started to empty out 50% of the water while aeration continued.  Slowly, the fish, shrimp, and snails stopped gasping at the surface.  After refilling, I found another female rasbora deep in the plants.  She had also died.

Two female rasboras died.  The shrimp are still alive.

What was interesting today was that  CO2 was much higher than it should have been, 40+mg/L according to the pH/KH table. There also wasn’t any pearling from any of the plants at any time during the day.  This was really odd.  But considering what happened, what was probably going on was that the bacteria was consuming so much oxygen that the plants couldn’t keep up with the demand.  When the photoperiod ended, the plants stopped photosynthesizing and oxygen levels dropped.  Then within an hour and a half, it crashed.  Luckily, I came down and noticed what was going on or I would have woken up in the morning and realized I had nothing to feed.

The water is still very turbid after a 50% water change.

I wont know the extent of the damage until tomorrow. It’s possible that there were more fish deaths but I can’t see through the turbidity.  There are two Otos but I can see only one swimming around.

DIY Magnesium from magnesium metal

Instead of using magnesium sulfate which can add unnecessary sulfate, magnesium metal can be used as a fertilizer after it has been dissolved in an acid.

Magnessium ribbon bought on eBay for $2.

Materials

1. Magnesium metal
2. Acid (vinegar, citric acid, etc.)

The white cloud are the tiny gas bubbles being released as the magnessium dissolves.

Instructions

Place the metal into the acid solution and it will immediately effervesce.  Once it fully dissolves, add it to the aquarium.

To calculate how much magnesium is added, simply divide the weight of the magnesium in grams by the tank volume in liters, then multiply by 1000mg/g to get the concentration in mg/L.  For example, 1g ÷ 100L × 1000mg/g = 10mg/L of Mg.

Where to Buy

A 25g magnessium ribbon can be bought on eBay for about $2 shipped.  The one I bought was 99.5% minimum purity with a maximum of 0.05%  Fe, 0.05% Mn, and 0.01% Pb (lead).  If you want higher purity, it can be bought at AlphaChemicals.com with a guaranteed minimum purity of 99.8% for $8 shipped.  They also sell magnesium chips, 250g for $15 shipped, which is a pretty good deal.

So if your water is low in magnesium and you don’t want to add any unnecessary sulfates, use magnesium metal instead.

CAUTION

If using vinegar as the chelant, the resulting acetate will be a source of organic carbon that bacteria will love.  This will result in a bacterial bloom that can use all of the available oxygen to deplete and suffocate the fish and other animals.  The more acetic acid you add, the larger the bacterial bloom.  So be sure to add an airstone to aerate the water.  The bloom will be short lived once all the acetate has been consumed.

DIY Calcium from eggshells

If you eat eggs, you can save the shells to make a natural alternative calcium fertilizer.  Instead of calcium sulfate, which can add unnecessary sulfate as well as high concentrations of lead and other undesirable heavy metals, eggshells are composed of 95-97% calcium carbonate, with the remaining consisting of proteins.

An eggshell on a gram scale.

Materials

1. Eggshell
2. Acid (vinegar, citric, etc.)
3. Container

Instructions

Clean the eggshell and place into the container.  Add vinegar and the shell will start to dissolve and fizzle, releasing CO2.  Once dissolved, remove the inner membrane and add into the aquarium.

CO2 gas is released from the eggshell as it slowly dissolves.

Another alternative is to dissolve the calcium carbonate with CO2 in solution. If the aquarium water is acidic, the eggshell can be placed directly into the tank to slowly dissolve.

How much calcium does an eggshell provide?

An extra large, grade AA eggshell weighs about 6 grams, not including the inner membrane.  Calcium is ~39% so one egg provides about 2.3 grams of calcium.  (6g × 0.39 = 2.3g)

To calculate the concentration of calcium, divide 2.3 grams into the volume (in liters) of the aquarium.  E.g. 100L aquarium results in 23 mg/L of Ca.

2.3g Ca ÷ 100L = 0.023g/L × 1000mg/L (converting g to mg) = 23mg/L of Ca

CAUTION

If using vinegar as the chelant, the resulting acetate will be a source of organic carbon that bacteria will love.  This will result in a bacterial bloom that can use all of the available oxygen to deplete and suffocate the fish and other animals.  The more acetic acid you add, the larger the bacterial bloom.  So be sure to add an airstone to aerate the water.  The bloom will be short lived once all the acetate has been consumed.