How much to dose your aquarium

[Country joe]

I have a 125 litre aquarium taking in substrate, wood, and rocks, how many litres would you take off, when it comes to dosing?

 

[AJ356]

Some people say take 10% off. 20% off is usually more realistic. For some of my set ups I take off 25%

 

[AJ356]

My answer is just based on water volume to give you an idea. I am not speaking about medication or additives, but if my tank is marketed as a 100 gallon and I have substrate and wood, I say it holds 80 gallon of water.

Obviously it depends on how much substrate, wood, rock etc.

 

[Essjay]

A number of manufacturers quote a volume which includes the thickness of the glass and the air space between the water surface and the tank rim. So you'll read recommendations to reduce the manufacturer's quoted volume of an empty tank, not just to include the substrate, decor etc.

This does not seem to apply to Juwel tanks though. The dimensions of the Rio 125 give 146 litres. Their quoted volume is the amount of water that tank will hold, but obviously doesn't allow for substrate, decor etc. But it is worth bearing in mind for other brands.

 

[Country joe]

So you would say mine would be 105 litres

My answer is just based on water volume to give you an idea. I am not speaking about medication or additives, but if my tank is marketed as a 100 gallon and I have substrate and wood, I say it holds 80 gallon of water.

Obviously it depends on how much substrate, wood, rock etc.

A number of manufacturers quote a volume which includes the thickness of the glass and the air space between the water surface and the tank rim. So you'll read recommendations to reduce the manufacturer's quoted volume of an empty tank, not just to include the substrate, decor etc.

This does not seem to apply to Juwel tanks though. The dimensions of the Rio 125 give 146 litres. Their quoted volume is the amount of water that tank will hold, but obviously doesn't allow for substrate, decor etc. But it is worth bearing in mind for other brands.

I aways thought that if it said 125 that meant the aquarium held 125 in litres when totally empty.

 

[Essjay]

With Juwel, yes it does mean that. When I had a Rio 125 there was a maximum water level marker inside the tank, and 125 litres was up to that marker when there was only water in the tank, no decor etc. Because the light unit sits below the rim, it is dangerous to have water above that marker so it is impossible to safely fill a Juwel tank right to the brim or the lights would be under water.

Other manufacturers have the lights above the rim of the tank so in theory those tanks could be filled to the brim, so that's the volume they quote. In practise, if a tank is filled to the brim the slightest disturbance would cause it to overflow so we leave a gap between the water surface and the rim, and the manufacturer's quoted volume does not allow for that air space. I've had a 54 litre tank which held 45 litres water and a 32 litre tank which held 25 litres water just because of that air space above the water surface. That's before adding substrate, decor etc.

 

[Country joe]

With Juwel, yes it does mean that. When I had a Rio 125 there was a maximum water level marker inside the tank, and 125 litres was up to that marker when there was only water in the tank, no decor etc. Because the light unit sits below the rim, it is dangerous to have water above that marker so it is impossible to safely fill a Juwel tank right to the brim or the lights would be under water.

Other manufacturers have the lights above the rim of the tank so in theory those tanks could be filled to the brim, so that's the volume they quote. In practise, if a tank is filled to the brim the slightest disturbance would cause it to overflow so we leave a gap between the water surface and the rim, and the manufacturer's quoted volume does not allow for that air space. I've had a 54 litre tank which held 45 litres water and a 32 litre tank which held 25 litres water just because of that air space above the water surface. That's before adding substrate, decor etc.

So with the juwel 125 would you knock 5 litres off for substrate decorations. As I always dose the tank for 120 litres

 

[Essjay]

I moved my Rio 125 across the room. I emptied it to move it then refilled in it's new position. I measured 105 litres water back in, but I did have some pieces of wood in the tank - if you have fewer things like rock or wood, yours will hold more water.

 

[Colin_T]

To work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

When you measure the height, measure from the top of the substrate to the top of the water level.

If you have big rocks or driftwood in the tank, remove these before measuring the height of the water level so you get a more accurate water volume.

You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" on the right side of this page that will let you convert litres to gallons if you need it.

Calculator

Remove carbon from the filter before treating with chemicals or it will adsorb the medication and stop it working. You do not need to remove the carbon if you use salt.