[ant]

Hello All,

After two back to back 50% water changes, a few tests show the aprroximate results:

PO4 5.0
NO3 70
KH 4.4dkh

Should I be concerned with any of these numbers? I know judgement and results are not accurate, but i just want to make sure. If I should be concerned, is there anything suggested to adjust the numbers?

I have a 46 gal, high light, co2 injected, EI doisng and med to heavy planting. 7 Ottos, 4 neons, 20 RCS and 2 nerites. I barely provide any food so I cannot imagine PO4 being high from leftover food. Fish and RCS are doing fantastic, but the plants have seen better days.

Others not so concerned with:
PH 6.6
GH 10dh
Co2 30ppm

Thanks!

 

[Diana]

I would reduce the dosing. Get the NO3 down to somewhere between 5-20 ppm. Perhaps 5-10ppm would be the target right after a water change, then dosing should raise that to double (10-20ppm) by the end of the week.
Similar concept with the PO4, but lower values. <1 right after a water change, then 1-2 ppm by the end of the week.

GH should suit the livestock. Soft water fish would prefer slightly lower GH. Research the fish and shrimp you keep to find the optimum value. If your water has 10dGH out of the tap, don't bother fighting it. Neon Tetras have been raised in captivity for so long they are OK with somewhat harder water than their ancestors.

 

[ant]

Thanks. I figure I will have to do some guessing with the dosing requirements to get the right amounts. I just did not understand how the levels were so high without extra interaction of other sources- besides the ones I seem to not know about!

 

[Diana]

Well, the sources of nitrogen in an aquarium are pretty basic:

Protein from food. The fish food either gets eaten by fish and the nitrogen is excreted by the fish via the gills as ammonia. Or the food is not eaten by fish, but is eaten by microorganisms which ultimately produce some form of nitrogen waste. Most of the nitrogen that enters the tank end up either in the plants, or building up as nitrate.

Nitrogen fertilizer. From liquids, root tabs, dry ferts... If the ingredients include nitrogen in any form, it may be used by the plants, or not. Generally it will end up at nitrate if the plants do not use it. Almost all nitrogen fertilizers will include the word Nitrogen, nitrate or similar terms. Urea is a nitrogen fertilizer that is not generally used in aquariums. In breaking down, it can produce ammonia.

Fallen leaves, and any other organic matter can also contribute ammonia and other forms of nitrogen as it decomposes.

Any other sources of nitrogen are so rare that it would take quite some detective work to find it.

 

[mredman]

I doubt that your food is the major source of the phosphates so I would question your fertilizer regime and water source. Consider using a mix of RO and tap water. Have you tested your source water for phosphate levels? You make 50% water changes but how often?

If you are using potassium phosphate, switch to potassium sulfate or potassium nitrate. I rotate with both.

Mike

 

[cjp999]

If you have well water, it could be high in nitrates. Mine is 40-50ppm. Even municipal water can be up to 40ppm if drawn from wells (they need to treat it get it below 40ppm to meet government standards).

 

[ant]

I do 50% H20 changes every sunday. I try to get as much debris- leafs, excrement etc. as possible. There is usually a good bit a fish excrement on the bottom. My tap water has little to no phosphate and nitrogen. I tested numerous times to make sure.

I will try switching to another source of k such as potassium sulfate and also lower my doses of NO3.