150 FOWLR High Nitrate

[rinconmike]

I have a 150 FOWLR. I do 20% water changes weekly (RO/DI Water and Instant Ocean Salt Mix). The tank has been running for just over 2.5 years.

My Nitrates are high. At one point I got them down to around 20 (a few months back) and I just checked and they are now over 50. I tested with a Hach test and need to try another test kit that reads over 50, but assume is is higher. The only thing I changed in the last 2 months is I started using a Nuclear Canister filter again. However, the nitrates might have been high then before I started that up again, I just do not recall when I checked last. I change the cartridge every 2 weeks. I know canister filters can become a nitrate issue, but I figured changing every 2 weeks it would not be. It is just secondary filter for mechanical and is TEEed off the main pump. It does catch a lot of junk.

Another thought is I have a wet/dry sump that I used to have bioballs in (around 9 months without them now) that I removed the balls and added 4 liters of Seachem matrix (takes up very little room) and added around 25 pounds of live rock on top. I do have filter media on top of the rock and below the drip tray, but maybe after the last 8 months tiny debris has made its way in the rock.

More info on my setup below.

My parameters are:

Salinity 1.024
PH: 8.3
Ammonia: 0
Nitrate over 50 with a Hach Test.
Temp 78-79

Fish in tank currently include:

30" Snowflake Eel in tank for 2.5 years
7" Porcupine Puffer in tank for 2 years 3 months
6" Red Breasted Wrasse in tank for 1.5 years
6" Banana Wrasse in tank for 10 months
4” Blue Hippo Tang in tank for 6 months
5" Bluethroat Trigger in tank for 5 months

I do not think I am feeding too much. I feed every other day, sometimes two days in a row and skip a day. If anything, I do not think I feed enough. I usually feed frozen mix and supplement with nori and NLS pellets.

I have around 85 pounds of pukani LR (around 60 in display, 25 in sump in smaller pieces) and 4 Liters of Seachem Pond Matrix (in sump). I do use a filter pad in the sump on top of the rock that I change every week with water changes.

I have an Octopus XP2000sss skimmer. It never performed great. More crud on the sides of the walls than going into the cup.

I typically run a Jumbo Reactor mixed with GFO and ROX carbon and change every two weeks.

For the plumbing, the return pump (BlueLine 55) feeds a TEE that goes to the tank returns (two corner returns) and then to a valve that feeds the canister filter, from the canister filter to the JBJ chiller, then a TEE to feed the reactor and back to the sump. So with that, water returns to the top of my sump from 4 tubes (the two tank corner overflows, one from the chiller, and one from the reactor.

When I am not running a nuclear filter cartridge, I do leave the filter hooked up and the water runs through. Just no cartridge.

Thanks for any input and or suggestions.

 

[bertoni]

Depending on what's in the canister, that might cause some problems. The bio-media seem to discourage denitrification. The source of the nitrogen is the food, but some filtration methods seem better than others at allowing denitrification. More of the SeaChem Matrix media might help. I think that's one of their artificial live rock products?

Other approaches include carbon dosing (vodka, vinegar, and the like) or a denitrator of some sort. Growing and harvesting a macroalga can do a lot, too.

For that matter, none of those animals are going to be bothered by the nitrate, so you could just ignore it.

 

[rinconmike]

thanks. I am getting more red slime algea and now what looks like some brown algae so I am thinking it is the nitrates. It is not horrible, but the red slime is spreading out slowly.

It is more than when I had just bioballs and not much live rock. Maybe it is a cycle thing? I have been without bioballs for only 9 months even-though the tank us up for just over 2.5 years.

I have more room in my sump so I might try a bunch more of the seachem matrix and also pull out the canister filter cartridge again. When I first looked a Seachem, a big selling point was the denitrifying bacteria. Seachmen Tech Support said it should be better than live rock and for my tank should only need 2 liters. I went with 4 liters because I have the room and four takes up so little still so that is why I added live rock in the sump. The matrix also looks like it will collect less junk than the LR rubble.
thanks,

Mike

 

[RegalAngel]

Don't look for matrix to solve the high nitrate issue. I have a 300g system with closed loop filtration system with a large pool canister filter followed by 40 liters of pond matrix. I also have an open loop with a SRO 5000 I skimmer.

My nitrates are 50-100 ppm on my FO system!

I have tried the bio pellets and carbon dosing, but the water becomes more cloudy due the increased bacteria and it is not acceptable.
I change 50-100g/week of water!

 

[rinconmike]

thanks. I just ran two more nitrate tests. One with an Instant Ocean Kit I had for around 2 years and it looks like nitrate is 20 ppm. I ran another with my Hach Kit that only goes up to 50 and looks like 50.

So maybe nitrate is not the issue.

I ran a Phosphate test with a Hanna 713 Checker and it said 0.07. I assume with the algae growing that my phosphate is actually higher than what the test reads since the algae is consuming some. I have some red slime, some red hair, and some what looks like Green hair on the corner overflows, as well as some newer brown. For the most part it is not bad, but I want to try and stop it before it does become bad.

I might try changing my GFO/Carbon weekly for a month instead of every two weeks. Maybe my Pukani Rock is leaching phosphates. I read on the forum some people having phosphates leached out for a while.

thanks again.

Mike

 

[bertoni]

I agree that changing the GFO more often might help. I might try that or I might just add more. Either way is reasonable. Changing it more often likely is somewhat more efficient if the dosing amount is tuned properly, since it'll reduce bacterial sliming of the media.

GFO can be regenerated, if cost becomes an issue. The process does require working with lye and muriatic acid, both of which are dangerous, though.