Chemistry making me scratch my head...

[Cwentz758]

So finally got some new testers. Finally got the Hanna Phosphate checker and a new Red Sea nitrate test kit. My tank looks good minus some diatoms on the sand which was thinking I have a silicate leach somewhere since my tank is a few years old (and has been moved a few times). I used to have a nice purple Coraline on my rock which has since gone away. Waiting on the silicate tester to come but in the mean time I have two other high levels.

phosphate was at .13ppm (Hanna)
Nitrate 50+ppm (Red sea)
Nitrate 0 (expired api tester) only used this just because I have it

And normal stuff
alk is 7.9
Ca is 480
Mg 1365
Salinity .026
Temp 78
RODI was 0 TDS out

like I said tank seems fine my hammer and Xenia seem to be growing and my sps frag seems...ok it’s new still figuring it out. And I have a HUGE Gsp rock that looks good but just isn’t spreading like it used to. Running a filter sock, Somatic 60s skimmer with Brs mini reactor with60/40 carbon/gfo. What else can I do to lower phos and nitrate I only feed once a day a small nugget of frozen brine and a seaweed clip for the tang every other day.

 

[GoVols]

Option-1

Do more or larger water changes and keep testing your Nitrates and Phosphates.

You want to be able to feed a reef, and not starve it.

 

[Cwentz758]

Option-1

Do more or larger water changes and keep testing your Nitrates and Phosphates.

You want to be able to feed a reef, and not starve it.

I’ve only been doing about a 10g change weekly. It’s a 75g system. I’ll have to start doubling it to 20 a week.

 

[GoVols]

I’ve only been doing about a 10g change weekly. It’s a 75g system. I’ll have to start doubling it to 20 a week.

Well, it's only one option.

Hope that others will chime in too.

If you tumble GFO in it's own reactor, you should be able to dial in your phosphates, slowly and very accurately too. When testing it's output water, it should test to about zero, but be sure to lower both parameters slowly.

 

[Jenuvio]

10g that’s 13% water change weekly, should be fine. Are you syphoning the sand?

Also I’ve heard Nori diet can produce lots of nitrate. Try to feed Nori 2-3 times a week.

 

[Dan_P]

So finally got some new testers. Finally got the Hanna Phosphate checker and a new Red Sea nitrate test kit. My tank looks good minus some diatoms on the sand which was thinking I have a silicate leach somewhere since my tank is a few years old (and has been moved a few times). I used to have a nice purple Coraline on my rock which has since gone away. Waiting on the silicate tester to come but in the mean time I have two other high levels.

phosphate was at .13ppm (Hanna)
Nitrate 50+ppm (Red sea)
Nitrate 0 (expired api tester) only used this just because I have it

And normal stuff
alk is 7.9
Ca is 480
Mg 1365
Salinity .026
Temp 78
RODI was 0 TDS out

like I said tank seems fine my hammer and Xenia seem to be growing and my sps frag seems...ok it’s new still figuring it out. And I have a HUGE Gsp rock that looks good but just isn’t spreading like it used to. Running a filter sock, Somatic 60s skimmer with Brs mini reactor with60/40 carbon/gfo. What else can I do to lower phos and nitrate I only feed once a day a small nugget of frozen brine and a seaweed clip for the tang every other day.

Interesting situation.

When was the last move?

Moving a system can be a big disturbance. The high nitrate level could indicate the denitrification bacteria population is weak. Might explain the coralline die off.

You are running GFO already, increase the amount and frequency of replacement to bring down the PO4. If the tank looks good, consider doing nothing.

How did you you identify the colored patches on the sand as diatoms? This hobby underestimates the difficulty of identifying microorganisms.

For an older system, the silicate level is typically low and where daily dosing is required to keep it detectable. You can confirm this with your tester.

I would read up on reasons for coralline die off.

There are many ways to bring down nitrate. Carbon dosing might require the least investment.

 

[Cwentz758]

10g that’s 13% water change weekly, should be fine. Are you syphoning the sand?

Also I’ve heard Nori diet can produce lots of nitrate. Try to feed Nori 2-3 times a week.

I syphon the sand and maybe it’s the seaweed but he eats it quickly.

Interesting situation.

When was the last move?

Moving a system can be a big disturbance. The high nitrate level could indicate the denitrification bacteria population is weak. Might explain the coralline die off.

You are running GFO already, increase the amount and frequency of replacement to bring down the PO4. If the tank looks good, consider doing nothing.

How did you you identify the colored patches on the sand as diatoms? This hobby underestimates the difficulty of identifying microorganisms.

For an older system, the silicate level is typically low and where daily dosing is required to keep it detectable. You can confirm this with your tester.

I would read up on reasons for coralline die off.

There are many ways to bring down nitrate. Carbon dosing might require the least investment.

last move was Nov 30, 2019 I was in that home for 3 years. I had a three elsewhere about the diatoms they’re just a dusting on the sand, not stringy and come back within hours of water change. I’ll do some reading for Coraline die

 

[Dan_P]

I syphon the sand and maybe it’s the seaweed but he eats it quickly.



last move was Nov 30, 2019 I was in that home for 3 years. I had a three elsewhere about the diatoms they’re just a dusting on the sand, not stringy and come back within hours of water change. I’ll do some reading for Coraline die

Nice setup. It does have the appearance of being newish.

I have patch in my sand that resembles the one in your photo. It’s even in the same location. Examing the sand grains under a microscope showed that it was a cyanobacteria colony, weaving its filaments through the sand grains, but not forming a mat on top of the sand like we often see.

 

[Jenuvio]

I'm thinking throw in some beneficial bacteria... check your ammonia.