How to reduce nitrates in a 6 month old reef tank

[Pachiman]

Hello everyone, I started this great hobby around 6 months ago, bought a 20 gallon (96 liters) tank and did the proper cycling for 2 months adding bacteria once a week until it was cycled. One recurring problem I've had since forever are high nitrates (no3).

My current stocking list in the tank is as follows:

Spoiler: stocking list

2 clownfish
1 blue cleaner wrasse

1 cleaner shrimp - 1 fire red shrimp
3 hermit crabs
2 BTA (one splitted after a power outage, but they are doing great)

2 Frogspawns
1 Torch
1 bubble
1 gorgonia
2 candy cane
1 Sarcopython
1 green star polyp (really small frag)
1 anthelia
lots of zoanthids (around 100 polyps)

I feed my fish frozed mysis twice a week, and a algae 3 or something, both from tropical (brand). I haven't dosed with anything for corals yet, I add 5ml on wed of all-for-reef, and I added some calcium as I had really low calcium. I do weekly water changes of 10% and test my parameters before the water changes with Salifert.

All corals/fish/invertebrates are doing extremely well, all polyps open perfectly fine, perfect growth, 0 algae problems. But still the nitrate problem bugs me a lot.

The current problem I'm having is my insane amount of nitrates. I feed my fish really small portions once a day, cleaned the sandbed and everything and still 0 luck. There is no way of lowering them.

Attached down here are the measurements, 21/8/22 is missing the no3 value because I didn't have more tests for it I had to buy a new one.

Also a picture of my tank, it is not up to date I added more stuff lately but its the only I could find.

 

[Miami Reef]

Very organized post. I really enjoyed how you put the fish list as a spoiler. Neat.

First, let’s just get the obvious stuff out of the way: Do you use 0ppm TDS water? Because ammonia (which will eventually turn into nitrates) can certainly be added if the TDS is higher.

What happened on August 28th, 2022 that caused such a jump? What tests are you using?

For nitrates, you can do a numerous amount of things: carbon dosing, adding a refugium, water changes, and some people even say live phytoplankton dosing lowered their nitrates.

There are other options (like a deep sand bed). Sometimes when nitrates are high without a lot of algae consumption, they just tend to stay that way. That’s why a lot of people like dosing a carbon source (which is limiting to the bacteria that convert nitrates to nitrogen gas).

My personal favorite way to lower nitrates is with carbon dosing. But you will find a way that works for you:

This article is very solid. Has good and accurate advice. I’d recommend reading through it: https://www.bulkreefsupply.com/cont...twater-aquarium-proven-techniques-for-success

 

[Steve180]

just do weekly water changes, dont go chasing numbers and add too much stuff into your tank

 

[Miami Reef]

just do weekly water changes, dont go chasing numbers and add too much stuff into your tank

I just realized OP’s tank is only 20 gallons.

Water changes is the easiest way IMO.

 

[Pachiman]

Very organized post. I really enjoyed how you put the fish list as a spoiler. Neat.

First, let’s just get the obvious stuff out of the way: Do you use 0ppm TDS water? Because ammonia (which will eventually turn into nitrates) can certainly be added if the TDS is higher.

What happened on August 28th, 2022 that caused such a jump? What tests are you using?

For nitrates, you can do a numerous amount of things: carbon dosing, adding a refugium, water changes, and some people even say live phytoplankton dosing lowered their nitrates.

There are other options (like a deep sand bed). Sometimes when nitrates are high without a lot of algae consumption, they just tend to stay that way. That’s why a lot of people like dosing a carbon source (which is limiting to the bacteria that convert nitrates to nitrogen gas).

My personal favorite way to lower nitrates is with carbon dosing. But you will find a way that works for you:

This article is very solid. Has good and accurate advice. I’d recommend reading through it: https://www.bulkreefsupply.com/cont...twater-aquarium-proven-techniques-for-success

I bought a RODI filter last week, been using my LFS RODI water as well, tested it a couple of times and it was close to 0.

I have no idea what caused the jump, I didn't do anything out of the ordinary and I use the Salifert NO3 (I tested in my LFS kits and the same results as well).

I wanted to add a refugium but I started this tank without a sump, and adding one now is out of the equation sadly.

I will check out the carbon dosing thing and read that article, I read some articles before posting but I don't trust random websites I just consult with my LFS for everything, and they said "wait until it lowers naturally".

Thanks for the help

 

[Pachiman]

I just realized OP’s tank is only 20 gallons.

Water changes is the easiest way IMO.

You think 10% is too low? Should I do 20%? I'm very strict with the water changes never missed one. Even when I had a really high fever thanks to COVID and barely could walk I did my duties.

 

[Miami Reef]

You think 10% is too low? Should I do 20%? I'm very strict with the water changes never missed one. Even when I had a really high fever thanks to COVID and barely could walk I did my duties.

I think 10% is too low to have a noticeable effect.

I’d do 50% (match the parameters and temp). It doesn’t have to be perfect, but close enough.

Do that and see if it makes a difference. Then go back to 10% a week once you reached your target level.

If nitrates are staying the same, great!

If not, I’d just add more water changes. Carbon dosing needs a skimmer so it wouldn’t be optimal in your tank IMO.

 

[Pachiman]

I think 10% is too low to have a noticeable effect.

I’d do 50% (match the parameters and temp). It doesn’t have to be perfect, but close enough.

Do that and see if it makes a difference. Then go back to 10% a week once you reached your target level.

If nitrates are staying the same, great!

If not, I’d just add more water changes. Carbon dosing needs a skimmer so it wouldn’t be optimal in your tank IMO.

I have a hang-on bubble magus E3 skimmer that is on 24/7

 

[Spare time]

10% is definitely way too little. There are some products you can add if you would like to try and lower it another way or prevent the accumulation being as much.

 

[cdnco2004]

I have a hang-on bubble magus E3 skimmer

Unrelated question:

Does it produce much micro bubbles? I have a couple of 20g longs with Fiji cubes AIO insert with no sump. I have been looking for a good Skimmer at this small size without much luck. Most all produce a crap ton of micro bubbles that screw up the view of the tank. I have tried like 6 different skimmers for small tanks all had the same micro bubble issue.

 

[Pachiman]

Unrelated question:

Does it produce much micro bubbles? I have a couple of 20g longs with Fiji cubes AIO insert with no sump. I have been looking for a good Skimmer at this small size without much luck. Most all produce a crap ton of micro bubbles that screw up the view of the tank. I have tried like 6 different skimmers for small tanks all had the same micro bubble issue.

The first 15 days more or less after I added fish and it kept growing the slime the tank looked like sparkling water but after it is 100% clear 0 microbubbles. It is an insane skimmer I couldnt recommend it more.

I have the oxygen tube 100% open and the output valve thingy 50% close.

In the out part where the water goes back to the system there is a small filter like sponge, that helps with the bubbles at the start, I removed that because it kept getting full of dirt and overflow the cup - even without that it doesnt produce microbubbles.

 

[razorskiss]

I recently added a reef glass nano skimmer to my 25 and it's tremendously effective at reducing nitrates. After running it for a few days to clear out dissolved organics, I now run it on a wifi timer that turns it on for a few hours each night to maintain healthy levels.

 

[killer2001]

What is your phosphate? Could be bottomed out on phosphate and the nitrates just keep piling on.