[Wet Thumb Forum]-Wet dry filter in 180 gallon tank

[For100]

Guys,

I am using a wet dry filter in my discus set up, which works great, as a matter of fact too good to be true. NO2 0ppm and NH4/NH3 0ppm and NO3 < 5ppm.

Now, my question is why my tank consumes 50ml/day of flourish nitrogen + 1/2 tps of KNO3 twice a week (+ all micro-nutrients + FE + PO4 in decent rate).

My plant grow is not that good (at least no what I expected to be with the rate of consumption of macro and micro nutrient). I have CO2, around 20 to 25 ppm and 1.5 WPG for lighting. I would imaging that NO3 would be in excess (based on the dosis I am using) given that I consider that the light is the limiting factor for plant grow.

I wonder if the wet-dry filter has anything to do with it. I don't know if the nitrification process works differently in the wet dry and converts nitrAtes and nitrItes in gas.

Thanks,

Freddy

[For100]

Guys,

I am using a wet dry filter in my discus set up, which works great, as a matter of fact too good to be true. NO2 0ppm and NH4/NH3 0ppm and NO3 < 5ppm.

Now, my question is why my tank consumes 50ml/day of flourish nitrogen + 1/2 tps of KNO3 twice a week (+ all micro-nutrients + FE + PO4 in decent rate).

My plant grow is not that good (at least no what I expected to be with the rate of consumption of macro and micro nutrient). I have CO2, around 20 to 25 ppm and 1.5 WPG for lighting. I would imaging that NO3 would be in excess (based on the dosis I am using) given that I consider that the light is the limiting factor for plant grow.

I wonder if the wet-dry filter has anything to do with it. I don't know if the nitrification process works differently in the wet dry and converts nitrAtes and nitrItes in gas.

Thanks,

Freddy

[Steve Hampton]

A couple of issues need to be considered.

1) How long has the tank and filter been established?

2) How many and what size are your Discus?

3) How much and how often do you make partial water changes?

4) What brand of test kit are you using and have you tested it against a reference sample?

[For100]

Steve,

The tank is about 1 1/2 years old. I have 12 medium to large discus (4 to 6 inches). I usually do a 30% to 40% water change once or twice a week, water parameter 3 or 4 Gh and 1 or 2 KH.

My test kit is aquarium pharmacetical, and no I have not run it against a reference sample. But I am sure that when I don't add nitrogen I run in deficit, my tenelus swords tell me that something is missing.....

[imported_russell]

kh looks a little low.

[For100]

It is a little bit low, but I need it that way to keep my pH at 6.1-6.2 with Co2 between 20 and 25 ppm.

And with water changes, I don't run the risk of a pH crash....

Do you know about the Nitrogen intake?. It seems high

[imported_shalu]

It is a bit high for 1.5wpg. Although I have not seen the effect with my commercial wet/dry on 100gallon, Koi pond people use a special version of wet/dry called "trickle tower" to eliminate most nitrate from water(turning into N2). Those towers have typically higher drip distance, 18inches or taller. You can do a search on koi forums and find tons of information on trickle tower.

[Steve Hampton]

Having seen the picture of your tank I'm fairly convinced that your nitrate kit is at least reasonably close. You seem to practice exceptional fish keeping husbandry. I would also bet heavily that you don't allow a buildup of detritus in your mechanical pre filter and therefore you bio-media also stays very clean. The major issue concerning wet/dry filters becoming nitrate factories centers on folks with poor husbandry practices and allowing the mechanical filter and bio-media to become clogged and fouled.

Also, large tanks don't need as high of wpg as medium to small tanks. The 1.5 wpg of light over your tank is very comparable to a 125G with the same light being (250-300W)over 2wpg...meaning I don't consider your tank to be low light at all. Considering your light and CO2 injection I would guess your tank would be using 2-3 ppm of NO3 per day. You are only adding 5 ppm per week with KNO3 additions verses what I'd think would be 15-20 ppm per week of nitrate "consumption". I am discounting the Seachem Nitrogen additions, but I don't think it adds very much. It certainly must be expensive at the rate you are using it though. Why are you using Seachem Nitrogen if you have KNO3?

[Margolis]

all I can say is that the plants are consuming the no3 one way or another. Wet/dry trickle filters do not consume no3, in fact they are one of the most efficient no3 generators you can get