oscar nitrate production

[Drstrangelove]

ive done a load of calculations on the effects of water changes on nitrate, done a whole thread on this, i was using an oscar in 100g of water as an example, no one seemed to know how much an adult oscar (being fed an average amount of pellets) would make in a 100g tank with good maintenance?

The amount of nitrate is derived directly from the amount of protein.

1) take the amount of food in grams (1 pound = 16 oz = 453.6 grams, or 1 oz - 28.349 grams)
2) multiply that times the net dry weight % (varies by food, for example squid is 32%, cod is 35%, raw shrimp is 40.7%. Pellets are typically high, over 85-92%)
3) multiply that by the protein % of the food (varies by food type)
4) multiply that by the nitrogen % (varies by original source, but averages ~16% of protein)
5) multiply that by the ammonia % (which is 82% of the nitrogen)
6) multiply that by 1000 to get mg of ammonia
7) multiply that by 2.706 to get mg of nitrite
8) multiply that by 1.3478 to get mg of nitrate

9) calculate the amount of water in the system in gallons
10) multiply that by 3.78544 to get the ~liters of water

Divide the amount from 8) mg of nitrate by the amount in 10) liters of water to get mg per liter which is the same as ppm.

That's afaik, the way to go from "food eaten" to ppm of nitrate added to a tank.

 

[justarn]

thanks dr very helpful

 

[Drstrangelove]

As a math example 1 ounce of 50% protein, 90% dry food in 120 gallons of water should create 3.68 ppm of nitrate.

 

[Lgw]

Hey Justarn, I know it's not exactly what you're looking for... But you may find it a little informative.

Here's a (dodgy) graph.. The biro X is nitrate reading, green X is water change percentage and the blue line just shows when I clean the filters.
The nitrate readings are my best guess at reading the API kit. You will see I use 15ppm in the graph, this is because I couldn't pick whether it was 10 or 20 on the chart lol..



I have 5 (average of) 10 inch oscars in approximately 450 gallons, a couple of pothos plants and marine pure bio spheres in the filter.

 

[Lgw]

Also, my tap water reads at 0ppm.

I'm due to change water again tomorrow, probably another 20%. Hopefully that's enough to stop/lower the nitrates climbing. I've been slack/busy recently lol...

 

[justarn]

http://aqadvisor.com/AqAdvisor.php?...AqSpeciesWindowSize=short&AqSearchMode=simple

seems to advise 25% change a week on a 75g and 18% on a 100g....?

wonder what nitrates they are aiming for?

 

[justarn]

assuming they would want total nitrates no more than 20ppm they would be saying a full grown oscar in a 75 will create on average 5ppm per week!?

 

[convict360]

I made a thread on this ages ago, with some interesting responses lol

Search "water changes for 90 gallon Oscar" with convict360 in search bar, it'll be the first result. Won't let me paste it here.

I think the consensus was something like 75% per week in a 90 gallon, not that I agreed with it.

 

[justarn]

I have a 14 inch oscar, anyone want to lend me a 100g tank!-) its bugging me that no-one can even give a ball park figure.... Must mean alot more people arnt even testing there water at all if no-one knows....

 

[Yuki Rihwa]

I have a 14 inch oscar, anyone want to lend me a 100g tank!-) its bugging me that no-one can even give a ball park figure.... Must mean alot more people arnt even testing there water at all if no-one knows....

Well, you're in UK...Can't help you with that (tank issue).
As for water testing I already said in general nobody gonna test their water weekly, monthly once their tank proper cycled they just stick to their schedule maintenance. How many Veteran fish keepers here testing their water on regularly basic (weekly/monthly)? I doubt that