Stubborn Nitrates

[Comic_Reef]

Good afternoon everyone,

I am finally posting here after doing lots of research, testing, waiting, testing, more research and yet I am still encountering the same problem for nearly 6 months. I cannot get my nitrates steadily down. This is not my first tank and have had success in the past.

Current Methods:
30g JBJ Rimless w/ Sump - 6 Months Old
Bubble Magus Curve 5 Skimmer
Kalkwasser + ATO
One Marine Pure Block in Sump
Small bit of Chaeto (Green and Growing)
No3Po4x Dosing (5mL per day)
Prodibio (Every 14 Days)
RODI - 0 TDS Water
Red Sea Salt (Blue Bucket)

Tests:
Nitrate: 25
Phosphate: 0.06
Mag: 1440
Cal: 420
Alk: 8.8
Ph: 7.8
Temp: 78.5

Livestock:
1 Ocellaris Clown
2 Blue Chromis
1 Shrimp Goby
1 Pistol Shrimp
1 Cleaner Shrimp
Many Snails

As noted above, I struggle to keep nitrates in check and low.
- I have been testing and dosing Phosphate regularly for 2.5 weeks as I struggle to keep it detectable. When I first noticed undetectable PO4, I began dosing daily to keep it above .02; now only doing this once every few days. Since beginning to dose PO4, my skimmate has seen a quite dramatic change is smell and color (dark and smelly). Nitrates have seemed to have stalled since doing this but no decline. Try to keep Phosphate at 0.05 until I can rebalance PO4 to No3. No noticeable algae in display.
- Did back to back 50% water changes to bring nitrates down from around 80-100.
- Chaeto used in conjunction with kalk and Co2 Scrubber to keep Ph above 7.8. Living in an 8 unit apartment building in Phoenix really affects my ability to keep PH respectable. (Rarely able to open windows)
- Have tested and cleared fresh ATO/Mixing water as a suspect.
- Feed very lightly (Small amount of flakes/pellets once every other day)
- Not feeding coral.
- Good flow, no signs of detritus collecting in any area of DT.
- Siphoned Back Chambers/Sump

Any Ideas?

 

[SPR1968]

As your already using Nopox I would personally increase the dosage by 1ml per day per week until you see the Nitrate start to drop and then slowly reduce back down until the nitrate stays were you want it. If you get any white slim just back off a little

I also have a marine pure block, but I have just added Seachem Matrix and I can say it’s made a dramatic difference very quickly. 18ppm to 7ppm nitrate and I have a massive bioload

I have used Nopox in addition for about 2 1/2 years and it’s just a matter of balancing it out.

The Matrix is the best bio media I’ve tried including marine pure and Brightwell NO3 blocks.

 

[cromag27 Verified Sponsor]

more big water changes. only way to really get them down. after that, work on husbandry.

 

[Comic_Reef]

As your already using Nopox I would personally increase the dosage by 1ml per day per week until you see the Nitrate start to drop and then slowly reduce back down until the nitrate stays were you want it. If you get any white slim just back off a little

I also have a marine pure block, but I have just added Seachem Matrix and I can say it’s made a dramatic difference very quickly. 18ppm to 7ppm nitrate and I have a massive bioload

I have used Nopox in addition for about 2 1/2 years and it’s just a matter of balancing it out.

The Matrix is the best bio media I’ve tried including marine pure and Brightwell NO3 blocks.

I have only briefly looked at Matrix before and have considered trying it. Did you use it to replace your Marine Pure Block or did you just add it in addition to the block.

 

[Comic_Reef]

more big water changes. only way to really get them down. after that, work on husbandry.

I have on multiple occasions water changed my way down to ~10 Nitrate only to watch them rise back to 80-100 over the course of a month or so. I'm not wholly convinced husbandry has been my issue. I've been doing multiple water changes a week, I actively siphon chambers/sump to keep them detritus free, siphon the small bits of detritus I see in the sand and turkey baster off my rocks prior to every water change. I held my previous tank in great standing with much less maintenance than this. All tanks are different, naturally, but its hard to believe naturally occurring differences would equate for an 80ppm difference.

Is it possible the previously low phosphate numbers threw off my Redfield Ratio so much is caused these problems?

 

[cromag27 Verified Sponsor]

how big are your normal water changes? how much/often do you feed?

 

[Comic_Reef]

how big are your normal water changes? how much/often do you feed?

I have been averaging 8 gallons (~25%) twice a week or 16 gallons (~50%) once a week, dependent on what my work schedule allows.
When i see nitrates over 50, i resort to two 16 gallon water changes on back to back days. to bring it back down to ~10.

I feed every other day right now because of the nitrate issue. A few flakes and a few sinking pellets for the goby, making sure they are consuming nearly everything I put in. Trying not to starve them but also very aware of the amount I'm putting in so as to avoid uneaten food.

 

[SPR1968]

I have only briefly looked at Matrix before and have considered trying it. Did you use it to replace your Marine Pure Block or did you just add it in addition to the block.

In addition to Marine pure which I still have in at the moment. But the Matrix seems far superior, but use more than you think you need. I have 6 litres which is enough for 4800 litres of water. My system is 650 litres but you can’t have to much filtration! And again I have a very big bioload which you can see from my build thread

I wouldn’t worry about the redfield ratio here, keep your phosphate locked down at around 0.o3ppm.

Your nitrates are not that bad anyway at 25pm but I appreciate you want to lower them and bring them under ‘your control’.

If you balance your bio filtration well, you can reduce water changes as the system will look after itself once established

 

[Comic_Reef]

In addition to Marine pure which I still have in at the moment. But the Matrix seems far superior, but use more than you think you need. I have 6 litres which is enough for 4800 litres of water. My system is 650 litres but you can’t have to much filtration! And again I have a very big bioload which you can see from my build thread

I wouldn’t worry about the redfield ratio here, keep your phosphate locked down at around 0.o3ppm.

Your nitrates are not that bad anyway at 25pm but I appreciate you want to lower them and bring them under ‘your control’.

If you balance your bio filtration well, you can reduce water changes as the system will look after itself once established

How are you currently running matrix? Bag, Filter, Reactor?
I agree that 25 is horrible at the moment, however I would like to see increased coral health, color and growth by lowing them a little but and hovering around 5-10 if possible.

 

[cromag27 Verified Sponsor]

I have been averaging 8 gallons (~25%) twice a week or 16 gallons (~50%) once a week, dependent on what my work schedule allows.
When i see nitrates over 50, i resort to two 16 gallon water changes on back to back days. to bring it back down to ~10.

I feed every other day right now because of the nitrate issue. A few flakes and a few sinking pellets for the goby, making sure they are consuming nearly everything I put in. Trying not to starve them but also very aware of the amount I'm putting in so as to avoid uneaten food.

you could be over feeding. you don’t have a lot of livestock. but i’d youre confident you’re not over feeding then i would up nopox. marinepure, matrix, etc are more for maintenance purposes but not really a solution to the root problem.

 

[Comic_Reef]

you could be over feeding. you don’t have a lot of livestock. but i’d youre confident you’re not over feeding then i would up nopox. marinepure, matrix, etc are more for maintenance purposes but not really a solution to the root problem.

I will begin upping 1ml per day. Thanks for the advice. I've always been afraid of overdoing it

 

[Porpoise Hork]

Dosing NoPox takes time. It may be a week or more before you see any results. I found that when I need to bring my nitrates down I dose SeaChem Stability along with the NoPox and and adjust the skimmer for a slightly wet skimmate. Also change the filter socks every two days and then do a couple large 25% water changes will bring it down quick.

 

[Captain Quint]

Mynameztwitch ~25 isn't that bad so it sounds as though you're doing a good job really.

If you like you could consider a BioPellet & Filter Media Reactor?

There are some good 4-star units out there for around $60. Takes about 4 to 6 weeks to start a noticeable reduction initially, but they work nicely.

 

[Captain Quint]

I have on multiple occasions water changed my way down to ~10 Nitrate only to watch them rise back to 80-100 over the course of a month or so. I'm not wholly convinced husbandry has been my issue. I've been doing multiple water changes a week, I actively siphon chambers/sump to keep them detritus free, siphon the small bits of detritus I see in the sand and turkey baster off my rocks prior to every water change. I held my previous tank in great standing with much less maintenance than this. All tanks are different, naturally, but its hard to believe naturally occurring differences would equate for an 80ppm difference.

Is it possible the previously low phosphate numbers threw off my Redfield Ratio so much is caused these problems?

I'm guilty of some pretty heavy feeding and I have to stay on top of the numbers as you do from time to time. 80---->100 is kinda scary to see but it appears that you definitely stay on top of it. I've seen mine at ~50 from time to time and kick myself in the rear so I get where you're coming from.

 

[Porpoise Hork]

Mynameztwitch ~25 isn't that bad so it sounds as though you're doing a good job really.

If you like you could consider a BioPellet & Filter Media Reactor?

There are some good 4-star units out there for around $60. Takes about 4 to 6 weeks to start a noticeable reduction initially, but they work nicely.

The Aquatop MR-20 media reactor is only $40 and works amazingly well for this. I am using it for dual purpose. I got some knitting mesh from the hobby store and made a guard for the bottom and put the bio-pellets on the bottom portion and put 2.5 cups of carbon on the top. The little 90g/hr pump is just right to tumble the pellets well and the carbon keeps the water polished to a crystal clear for my 75g.

 

[lmm1967]

I fought a similar challenge for a long time. Then I did this. https://www.reef2reef.com/threads/poor-man-nutrients-control-donovans-nitrate-destroyer.302685/. It took about 3 weeks before I could measure a difference between the inbound flow versus the outbound flow. A couple weeks later I was below 5 ppm nitrates.

Now I've had to take it off line and am considering dosing nitrates because I'm consistently below 1 - generally .25

 

[SPR1968]

How are you currently running matrix? Bag, Filter, Reactor?
I agree that 25 is horrible at the moment, however I would like to see increased coral health, color and growth by lowing them a little but and hovering around 5-10 if possible.

I purchased the large zip bag to put it in just to keep it all together in my sump.

If you haven’t seen it, it’s just like stones/pebbles and has a long life span so shouldn’t ever need to be replaced

25 isn’t that bad but like you I prefer to be around 5-10 myself as I feel more in control of the overall system

 

[Comic_Reef]

I purchased the large zip bag to put it in just to keep it all together in my sump.

If you haven’t seen it, it’s just like stones/pebbles and has a long life span so shouldn’t ever need to be replaced

25 isn’t that bad but like you I prefer to be around 5-10 myself as I feel more in control of the overall system

So I emptied out the skimmer (darkest skimmate I've seen on this tank, I turned up my skimmer a bit and dosed some more phosphate as I was measuring at 0.02.

I think my Hannah ULR checker may be off a bit since it never seems to display anything under 0.02, even in fresh RODI water. I usually just consider that a zero reading.

I think I am going to keep this pace for another week and see what my readings show. The dark skimmate gives me hope that the phosphate dosing is helping to re-balance things and is letting the bacteria split and process nitrate more efficiently. While I wait, I will definitely dig into the ins and outs of Matrix. It's definitely an avenue I'm open to pursuing should the PO4 not help. Nothing happens fast in this hobby and i'm trying to stay patient and level headed.