Nitrate Reduction in AIO

[Bubblebass]

I downsized to a 40g AIO that's about 2 years old. Having a really tough time keeping the nitrates in check. Always remain around 30. Religious about water changes, have a small skimmer that pulls very little, feed light and have a light bio load. I have no room or desire for a refugium or scrubber with this tank.

Carbon dose?

I'm open to suggestions.

 

[Newguy101]

Do you ever siphon out the rear chambers? Don't resort to carbon because all you're doing is putting a bandaid on a different issue.

 

[Newguy101]

Also, corals use nitrates as well, so perhaps you don't have enough organisms in the tank using up the available nitrates. Just a thought.

 

[ZoWhat]

Absolutely

I couldn't imagine not carbon dosing. Ive been dosing btwn 5-10ml of 80proof Vodka every morning and im stable at 10ppm. High enough for corals to feed off the nitrates.

 

[Newguy101]

Absolutely

I couldn't imagine not carbon dosing. Ive been dosing btwn 5-10ml of 80proof Vodka every morning and im stable at 10ppm. High enough for corals to feed off the nitrates.

Don't you think there's an underlying issue tho? Just an honest question.

 

[ColoredRock]

80Gal water volume here.. .5ml (noPox) a day keeps it at bay.

.05 Phos
35 Nitrate (working on lowering it slowly)

 

[ZoWhat]

Don't you think there's an underlying issue tho? Just an honest question.

Nitrates and Phosphates are naturally occurring.

Like Oxygen and CO2 in the air....

You can't avoid no3....just manage it thru smart food choices and amounts..... and carbon dosing

 

[AJsReef]

What’s your stocking?

What’s the volume and frequency of your water changes? Do you test nitrate before and after?

 

[Newguy101]

Nitrates and Phosphates are naturally occurring.

Like Oxygen and CO2 in the air....

You can't avoid no3....just manage it thru smart food choices and amounts..... and carbon dosing

I completely understand it's naturally occurring and unavoidable. But if anything, add more coral to absorb the nitrates. I have problems keeping nitrates above 0 in all of my AIOs(bare bottom tanks) with only a skimmer and water changes. But it's not really a problem, any ammonia being converted to nitrates is immediately taken up by the coral, therefore I can feed a TAD bit more a few times a week. I just don't understand how some people are able to keep it at bay without dosing anything and others have issues keeping it down without dosing. To me that says it's a balancing issue going g on.

Edit: actually the tank I usually always have 0 nitrates in, doesn't even have a skimmer, and it's used as a frag tank with plenty of growth

 

[damsels are not mean]

how much coral do you have

 

[OrchidMiss]

Do you ever siphon out the rear chambers? Don't resort to carbon because all you're doing is putting a bandaid on a different issue.

Yep! I'm new to AIOs, but literally last night I was looking in the back and saw everything settled on the bottom. Luckily, with my job, I'll use medical supplies to be able to suction out back there for water changes.
Lol I'll post a photo when I set it up this weekend!

 

[ColoredRock]

I just don't understand how some people are able to keep it at bay without dosing anything and others have issues keeping it down without dosing.

that is part of the fun of it.. so many things that happen just going into our tanks. RODI = TDS 0.. is it?, Environmental conditions regarding just the carbon influence in the living space the tank is in. Cats, dogs, BIRDS.. age of the house.. etc.

 

[Bubblebass]

What’s your stocking?

What’s the volume and frequency of your water changes? Do you test nitrate before and after?

I do 7 gallons a week. They stay steady all the time at 30-40. At 20% water changes, nitrates only would drop max of 6.

 

[Bubblebass]

I have 2 fish and a lot of coral. RODI is 0 tds from a 7 stage system. I do suck out the back “sump” area during water changes.

 

[MaxTremors]

Don't you think there's an underlying issue tho? Just an honest question.

Its not any more of a bandaid than a refugium or water changes. In the ocean there is a constant carbon source that helps complete the nitrogen cycle, most of our tanks are very carbon limited and so the nitrogen cycle stops at nitrites turning into nitrates. By adding a carbon source, you’re allowing some nitrates to be converted to nitrogen which then gasses off, and some nitrates are removed as bacterial biomass by the skimmer (and eaten by corals/filter feeders). The latter type of removal (bacterial biomass) is the exact same concept as a growing macroalgae, you’re encouraging the growth of biomass (whether algae or bacteria) which consumes and holds nitrates (and to a lesser extent phosphates), which are then removed through skimming or through pruning back your macroalgae. You’re removing stuck nitrates as biomass.

There may be an underlying issue of over feeding or lack of water changes or proper nutrient export, but carbon dosing is a natural way of keeping nitrates in check.

 

[Bubblebass]

Absolutely

I couldn't imagine not carbon dosing. Ive been dosing btwn 5-10ml of 80proof Vodka every morning and im stable at 10ppm. High enough for corals to feed off the nitrates.

What is your total volume?

 

[305]

Make sure ur running the pump chamber water level low enough that ur media baskets are just sitting in stagnant water
Had a frien recently that didnt use the min max indicator on her bio-cube.. always had high everything theyd climb almost by the day
Now the wayer trickles thru her media and keeps em at bay for weeks without wc

 

[Newguy101]

Yep! I'm new to AIOs, but literally last night I was looking in the back and saw everything settled on the bottom. Luckily, with my job, I'll use medical supplies to be able to suction out back there for water changes.
Lol I'll post a photo when I set it up this weekend!

Exactly. Even if you run a skimmer and filter socks, stuff still gets through and settles... ill see if I can upload a photo of what I pulled out 2 days ago out of the back chambers in one of mine(back chambers get vacuumed about once a month or 2, depending on what the tank is doing)

 

[ZoWhat]

What is your total volume?

180g DT = 220 volume

 

[AJsReef]

I do 7 gallons a week. They stay steady all the time at 30-40. At 20% water changes, nitrates only would drop max of 6.

That’s pretty accurate to the reduction you’d expect to see then. 50% WC should net close to 50% reduction in nitrates. May be worth a 50% water change and see. Then record how quickly the nitrates raise again.

What two fish do you have?

If nitrate is rebounding quickly and stocking is reasonable it’s definitely worth investing more time to figure out why. As others have shared; cleaning back chambers would be one possible method to help lower. Potentially cleaning the sand bed as well.