Solid Method of Nitrate Reduction

[Drew1600]

Greetings all,

"Keep your nitrates low" is the center of many posts and articles across the web, but few of these actually explain how..

I run 2 tanks, a 13.5 gallon mixed reef and a 6 gallon mixed reef. My nitrates are consistently 20-30 in the 13.5 gallon and 20-40 in the 6 gallon. Even after multiple water changes I am unable to bring the nitrates below 20. The 6 gallon has a single clown goby, sand, live rock, 2 mangroves, and some macro. Filtered by an AquaClear 50. The 13.5 has a Cascade 500 canister filter, a pair of clownfish, and a blue damsel. Live rock and sand also.

I would be happy to keep both tanks in the 15-20 range but lower would be preferable. I have tried Seachems denitrate with no luck and api nitrazorb with little luck so far. My phosphates test 0-0.25 via api test.

I wc the 13.5 weekly and the 6 gallon twice a week as of lately.

My question is, does anyone have a solid method of nitrate reduction? And if its carbon dosing, do you use a specific product? Thank you!!

 

[Drew1600]

Forgot to add I fill my tanks with well water, should not be any nitrate present initially.

 

[BigRed78]

Test the well water for nitrate

 

[Drew1600]

Well water tested zero.

 

[moreef]

Well water tested zero.

Did you test with saltwater or freshwater? Not sure if it makes a difference or not.

 

[Drew1600]

The freshwater. I can test salt too, worth a shot. I use Fritz blue box.

 

[Tired]

You really need to figure out what your phosphates are. Having that too low will kill your corals. It can also hinder the uptake of nitrates, as photosynthetic organisms need both nitrates and phosphates to grow and function, and won't use up one if the other is present.

Are the nitrates causing any problems that you can see? Stressed coral or the like?

 

[Dkmoo]

Refugium or algae scrubbers. WC is actually a very ineffective way of reducing nitrate unless you do like a single 80% 90% wc.

Doing multiple smaller WCs with increased frequency doesn't really work either bc of how the math works -- whats not obvious is how much nitrate increases each day and the multiplicative affect. For example, if your tank sits at 40ppm by the time you do your 30% weekly Wc, that means your tank produces 40× 30% =12ppm a week, or approx 2ppm a day. So even if you do 3 30% wcs every other day the following week, your nitrate levels will be 40×.7= 28 after the first wc, (28+4)×.7=23 after second wc, (23+4)x.7 =19 after third WC, and by weeks end, you will be back at 19+4=23 ppm of nitrate. So, in what "feels" like you did a 30% ×3 = 90% wc for the week has only reduced your nitrate by less than 50% (40 to 23). Thats why you struggle to get it below 20% even by doing many WCs

 

[Drew1600]

Thank you so much, I may have to look into an algae scrubber or adding chaeto, its just hard to find around here. This makes perfect sense. I tend to do 30% wc and then refill the tank, I repeat until my 5 gallon bucket is full. As far as phosphates go, I just need a better test kit. My results are as accurate as API's test kit gets. No major signs of stress, colors could be brighter and minor deflation in certain species (like kenya tree).

 

[Reef.]

Thank you so much, I may have to look into an algae scrubber or adding chaeto, its just hard to find around here. This makes perfect sense. I tend to do 30% wc and then refill the tank, I repeat until my 5 gallon bucket is full. As far as phosphates go, I just need a better test kit. My results are as accurate as API's test kit gets. No major signs of stress, colors could be brighter and minor deflation in certain species (like kenya tree).

pick up a Salifert phosphate kit, they are cheap, hard to read at the low end but if you only want to keep your tank below .1 PO4, then it’s easy, any blue in the test then you are probably too high in PO4.

 

[HuduVudu]

I dose nitrates and I add 20ml of phytoplankton a day. My nitrates are at .2ppm. When I dose I try to get them to 25 ppm. This will only hold for 3 days.

 

[Drew1600]

I will pick one up, thank you so much for the input!

 

[Drew1600]

How did you manage to get it so low initally?

 

[Reef.]

I dose nitrates and I add 20ml of phytoplankton a day. My nitrates are at .2ppm. When I dose I try to get them to 25 ppm. This will only hold for 3 days.

what did your 20g run at?

 

[HuduVudu]

what did your 20g run at?

What do you mean?

 

[Reef.]

What do you mean?

I checked out your build thread, I think you have/had a 20g and a 65g? I was wondering if your quoted parameters were in reference to your new tank or your 20g?

 

[Biokabe]

Thank you so much, I may have to look into an algae scrubber or adding chaeto, its just hard to find around here. This makes perfect sense. I tend to do 30% wc and then refill the tank, I repeat until my 5 gallon bucket is full. As far as phosphates go, I just need a better test kit. My results are as accurate as API's test kit gets. No major signs of stress, colors could be brighter and minor deflation in certain species (like kenya tree).

If you can come up with a way of using chaeto on your tanks (it's tough with tanks that small, though not impossible) you can always get some chaeto from AlgaeBarn. Not too expensive, and it's only $45 for free shipping if you're not picking up something that needs overnight shipping. You should only need to buy it once - right now, I'm pulling about a softball's worth of chaeto from my refugium every week. Once you get something up and running, you should be able to seed the other tank from the first one.

 

[blasterman]

You're running small tanks with external, mechanical filters. What's the question again? Basically you are insuring high nitrate levels by doing this.

Small tanks don't need mechanical filters. Unless you clean and scrub the filtering media daily is quickly houses beneficial bacteria that should be in your tank on rocks and in substrate where there is some degree of nitrate reduction. These bacteria instead migrate to areas of the highest water flow and surface area. That just happens to be inside your mechanical filters.

If you are running bio media in either filter you are making the problem even worse. That's for the bare bottom goldfish feeder tank at the pet store. Not a salt water tank. If you are going to run a cannister 24/7 on a salt water tank you might as well be running bio wheels or a wet dry. You want nitrate you got it.

 

[HuduVudu]

I checked out your build thread, I think you have/had a 20g and a 65g? I was wondering if your quoted parameters were in reference to your new tank or your 20g?

They are for the 20g. The 60g runs at 25ppm pretty consistently. Turns out that chloramine has just come to my water supply so for a while I was dosing with water that had chloromine. So far no impact on either tank.

Just tested the 60g and looks like it is holding at 25ppm. That tank gets fed white worms 4x a day, so it has a pretty heavy load. I do expect in time for the nitrates to start dropping.

Going to try to get new pictures up of the 60g up on my build thread, but still no algae problems. Light dusting of brown algae on the dead rocks, but nothing significant yet. This is pretty standard for my tanks.

EDIT: I also dose the 60g with 20ml of phyto a day.

 

[Reef.]

They are for the 20g. The 60g runs at 25ppm pretty consistently. Turns out that chloramine has just come to my water supply so for a while I was dosing with water that had chloromine. So far no impact on either tank.

Just tested the 60g and looks like it is holding at 25ppm. That tank gets fed white worms 4x a day, so it has a pretty heavy load. I do expect in time for the nitrates to start dropping.

Going to try to get new pictures up of the 60g up on my build thread, but still no algae problems. Light dusting of brown algae on the dead rocks, but nothing significant yet. This is pretty standard for my tanks.

EDIT: I also dose the 60g with 20ml of phyto a day.

sorry just to be clear, your 20g runs at 0.2ppm nitrate but you dose to increase that to 25ppm?