Vodka dosing issue...

[Joe w1994]

I have been trying to increase vodka dosing on my 800 gallon shark pond and everytime I try going over 13 m/l the water gets blurry. What can I do to avoid this. Running a sro 6000 ext and a regal 300 skimmer. Any help or ideas whats causing it would be appreciated. Dose all my other tanks and never have had this issue.

 

[EnterName]

You get bacteria blooms when you're adding too much carbon. By dosing alcohols into your system, you're providing bacteria with what was apparently a limiting resource (organic carbon), and once you lift that limitation, they spread through the entire water column faster than they end up in the skimmer. This can also cause excessive bacterial growth in your tank's plumbing or power heads, so be careful not to clog anything.

Carbon dosing can only do so much before it starts causing issues, so I can't recommend increasing the amount you're using if you're already experiencing bacteria blooms. These blooms consume a lot of oxygen, and sooner or later you might end up feeding bacteria that aren't beneficial.

If you're trying to reduce nutrients with carbon dosing, you may have hit the limit and will need to resort to other means, or at least distribute the dosing throughout the day in very small amounts with a dosing pump. I would however recommend phosphate adsorbers like granular ferric oxide (GFO) for phosphate issues and water changes for nitrate issues instead.

 

[Joe w1994]

You get bacteria blooms when you're adding too much carbon. By dosing alcohols into your system, you're providing bacteria with what was apparently a limiting resource (organic carbon), and once you lift that limitation, they spread through the entire water column faster than they end up in the skimmer. This can also cause excessive bacterial growth in your tank's plumbing or power heads, so be careful not to clog anything.

Carbon dosing can only do so much before it starts causing issues, so I can't recommend increasing the amount you're using if you're already experiencing bacteria blooms. These blooms consume a lot of oxygen, and sooner or later you might end up feeding bacteria that aren't beneficial.

If you're trying to reduce nutrients with carbon dosing, you may have hit the limit and will need to resort to other means, or at least distribute the dosing throughout the day in very small amounts with a dosing pump. I would however recommend phosphate adsorbers like granular ferric oxide (GFO) for phosphate issues and water changes for nitrate issues instead.

On a smaller system id agree on performing water changes but on a system this large I dont think it seems very feasible, considering i would probably be changing 300 gallons give or take a week or 2 to keep nitrates at a desired level.

 

[Privateye]

You could use a denitrification reactor instead. It's still possible to get some cloudiness if you're overdosing a lot (rare IME) but since the carbon would be introduced to the water going into the reactor, the bacteria in the reactor would get the first opportunity to consume it. That would leave less available in the water column of the tank for the planktonic bacteria to proliferate.

 

[Joe w1994]

You could use a denitrification reactor instead. It's still possible to get some cloudiness if you're overdosing a lot (rare IME) but since the carbon would be introduced to the water going into the reactor, the bacteria in the reactor would get the first opportunity to consume it. That would leave less available in the water column of the tank for the planktonic bacteria to proliferate.

Which would you reccomend for my system?

 

[EnterName]

On a smaller system id agree on performing water changes but on a system this large I dont think it seems very feasible, considering i would probably be changing 300 gallons give or take a week or 2 to keep nitrates at a desired level.

Fair point, I forgot about the size of the system, sorry about that.

I like Privateye's idea. Macro algae reactors, biomedia reactors, reverse flow deep sand beds, and other solutions might be able to help a bit. It depends on how much you can fit in your sump. You can also try to get a second or simply larger skimmer if possible. The more dirt you get out, the better.
The more tedious option would be to rinse rocks you can take out in a bucket with tank water to get rid of a lot of detritus that is just decaying and releasing nutrients. You could also start replacing the substrate in small batches, which is another detritus trap. Adding some dead dry rock in the sump if you have space left can also help by offering more surface area for beneficial bacteria. There are many small improvements, but nothing will immediately bring your nitrates down.

If your tank is running fine, you might also be able to simply ignore the nitrate readings. If you read through Randy's article on nutrient target ranges, you will see that many very good-looking tanks have very high nitrate levels and seem to run without any problems.

 

[Joe w1994]

Fair point, I forgot about the size of the system, sorry about that.

I like Privateye's idea. Macro algae reactors, biomedia reactors, reverse flow deep sand beds, and other solutions might be able to help a bit. It depends on how much you can fit in your sump. You can also try to get a second or simply larger skimmer if possible. The more dirt you get out, the better.
The more tedious option would be to rinse rocks you can take out in a bucket with tank water to get rid of a lot of detritus that is just decaying and releasing nutrients. You could also start replacing the substrate in small batches, which is another detritus trap. Adding some dead dry rock in the sump if you have space left can also help by offering more surface area for beneficial bacteria. There are many small improvements, but nothing will immediately bring your nitrates down.

If your tank is running fine, you might also be able to simply ignore the nitrate readings. If you read through Randy's article on nutrient target ranges, you will see that many very good-looking tanks have very high nitrate levels and seem to run without any problems.

No problem. Wouldn't mind trying different things to reduce nitrates just dont know how to size it up for this size system.. for normal fish I would agree and not think much of it, but i believe as I've read sharks are far more sensitive to high nitrates than other fish.