Brute gray trash can leaching nitrate into RODI water

[KaneMN]

Hey reefers,

I’ve been storing my RODI water in a 32 gallon brute gray trash can (labelled food grade) for my WC. I also add powerhead and heater to keep water oxygenated and warm (78 F). Out of curiosity, today I checked my RODI for nitrate and phosphate. I found a small trace amount of nitrate (near 0, less than 2 ppm, from RS test kit) and 0 phosphate (salifert PO4 profi test). However, when I checked my water that has been stored in the brute, I have nitrate spike up to 2 ppm, while phosphate is at 0 ppm. Have anyone had experienced the same result? I have some diatom issue, but at manageable level (mostly on the walls and everything in the walls but not so much on the rocks or sand bed). Is this why I have diatom problem? I need to buy a test kit for silicate to see if my RODI water have silicate or not. Other than 10%WC and cleaning the walls. Feed fish once a day. Coral AB+ once a week, 5 mL phytoplankton for my pods once a day. Blue channel at 42% white at 2%. Blue on for 10 hours, white on for 4 hours. What can I do to reduce diatom bloom? TIA!

Tank parameter as of 12/30/20

Salinity 1.026
pH8.2
dKH 11
Phosphate 0.1 ppm
Nitrate 0 ppm
Calcium 460 ppm
Magnesium 1600 ppm
Ammonia 0 ppm
Nitrite 0 pom

Inhabitants in run protein skimmer and HOB fuge with cheato and GFO bag
2 clowns
1 yellow goby
2 fire gobies
1 captive bred mandarin goby
1 pistol shrimp
5-7 hermit crabs
1 emerald crab
3 turbo snails
4 nassarius snails
Other CUCs that I don’t remember the name lol
4 rock flower anemones
Bunch of corals

 

[Cell]

I'd be inclined to think it's a testing error or contamination in the Brute.

 

[Cell]

I think @Randy Holmes-Farley has said in the past he uses or used these extensively. Like a small army's worth and never had issues.

 

[Biglew11]

Nitrates don't cause diatoms, silicates do I've been using these for 4.5 years now no issues.

.1ppm phosphates in your tank is pretty good .03-.1 is generally recommended. Be careful of the gfo, it can strip your tank of phosphates very fast. You may want to feed more or dose nitrates to get them above zero. Generally want them around 3-10ppm.

 

[homer1475]

Been using grey brutes for 10 years. Never measured any nitrates in my stored SW.

 

[KaneMN]

I'd be inclined to think it's a testing error or contamination in the Brute.

Unfortunately I don’t have any other kits to test nitrate. I may take my water to the LFS

 

[KaneMN]

Nitrates don't cause diatoms, silicates do I've been using these for 4.5 years now no issues.

.1ppm phosphates in your tank is pretty good .03-.1 is generally recommended. Be careful of the gfo, it can strip your tank of phosphates very fast. You may want to feed more or dose nitrates to get them above zero. Generally want them around 3-10ppm.

I’ve tried so hard to bring nitrate up in my tank but it always stay at 0 ppm.

 

[KaneMN]

Been using grey brutes for 10 years. Never measured any nitrates in my stored SW.

Perhaps this is a bad batch or the production quality has changed? I just bought this recently.

 

[Cell]

I'd probably wash out the Brute in question really good with bleach, give it a thorough rinse, let it fully dry then do another test.

 

[homer1475]

Maybe I missed it, but what test kit are you using? 2ppm sounds like a margin of error in th etest kit depending on which kit was used.

 

[KaneMN]

Maybe I missed it, but what test kit are you using? 2ppm sounds like a margin of error in th etest kit depending on which kit was used

Red Sea kit

 

[dank reefer]

How often are you cleaning the brute cans? Could be residual build up over time

 

[homer1475]

If I'm to be completely honest, I've never cleaned my mixing barrels. I even use IO and have no brown crud in my barrels.

 

[GlassMunky]

I’m also gonna say I believe it to just be the Margin of error in the test kit.
2ppm is nothing

 

[dank reefer]

If I'm to be completely honest, I've never cleaned my mixing barrels. I even use IO and have no brown crud in my barrels.

When I used Reef Crystals I never had an issue with the elusive brown crud. But using red sea blue bucket has made the elusive brown crud show itself.

 

[KaneMN]

How often are you cleaning the brute cans? Could be residual build up over time

I bought it 2 months ago and I cleaned it like a month ago.

 

[KaneMN]

When I used Reef Crystals I never had an issue with the elusive brown crud. But using red sea blue bucket has made the elusive brown crud show itself.

Yeah, I used to store premixed IO reef crystal saltwater in this brute and got brown crude, so I dumped the whole thing out and stored only RODI.

 

[KaneMN]

I’m also gonna say I believe it to just be the Margin of error in the test kit.
2ppm is nothing

I will try to check again later

 

[Antics]

Not sure which Red Sea kit(s) exist for Nitrate but a quick google showed one of their NO3 kits is accurate within 2ppm, which is obviously possible for your situation. I too have been using brutes for close to ten years and have never had an issue. It seems quite likely this is a margin of error issue and not leeching.

 

[KaneMN]

Not sure which Red Sea kit(s) exist for Nitrate but a quick google showed one of their NO3 kits is accurate within 2ppm, which is obviously possible for your situation. I too have been using brutes for close to ten years and have never had an issue. It seems quite likely this is a margin of error issue and not leeching.

This is the Red Sea kit I’ve been using. Thanks for the reco. I will look into it.