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Rodi water questions phosphates

nightmarepl

NJRC Member
So I’ve ran an rodi for water changes for 2 years now replaced the canisters few times now..
so i checked my fish tank and I’m at .88 on hanna
I checked my rodi with reef crystal mix and it’s .09 shouldn’t that be 0?
Can’t figure out how the hell to bring down my phosphates tanks started to get invaded by cyano algae basically 3 days in invasion…

trying to get my sump setup better running my skimmer basically higher skim to dump every 3 days

tried using chemiclean it cleans it up but comes back after the 2 waters changes
 

Foxchase

NJRC Member
Chemiclean is more of a bandaid. You need to fix the root of the problem. In this case, test the TDS of you filter and make sure it's 0. For the phosphates in your tank, you should use gfo to bring them down
 

Rjmul

NJRC Member
Bronze Member
Do you test your rodi water with a tds checker
This is a good place to start. check it into the rodi and out of the rodi. Next step is test for phosphate in the fresh water. I'm ok with some measurable phosphate in saltwater. This stuff is usually mined
 

nightmarepl

NJRC Member
I haven’t tested my rodi with a tds in quite some time and frankly i had a cheapo one not sure if it was reading good which one do y’all use?
but when test the rodi for phosphates with Hanna it like .03 when i test the saltwater mix it’s 0.08ish usually which i figured should be semi ok tank should of been able to break that down

but reading 0.88 on the display is pretty insane
I never ran gfo was always alittle scared to use to plus introducing another monthly expense kinda sucks
 

Rjmul

NJRC Member
Bronze Member
I haven’t tested my rodi with a tds in quite some time and frankly i had a cheapo one not sure if it was reading good which one do y’all use?
but when test the rodi for phosphates with Hanna it like .03 when i test the saltwater mix it’s 0.08ish usually which i figured should be semi ok tank should of been able to break that down

but reading 0.88 on the display is pretty insane
I never ran gfo was always alittle scared to use to plus introducing another monthly expense kinda sucks
Well there's part of your answer. Seems like some of the phosphate is coming from your salt mix. How do the corals look ? My tank has been running around .76, and corals seems fine... I've been walking it down because that's what you're "supposed to do" but who really knows if it matters. In this photo I'm running around .38
 

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nightmarepl

NJRC Member
Well there's part of your answer. Seems like some of the phosphate is coming from your salt mix. How do the corals look ? My tank has been running around .76, and corals seems fine... I've been walking it down because that's what you're "supposed to do" but who really knows if it matters. In this photo I'm running around .38
We’ll my tank is infested with red cyano algae in the sand bed mostly the more i vacuum the more sand bed i pull which sucks i like a deep sand bed…
 

nightmarepl

NJRC Member
I’d start here try and your ppm below 5 ideally you want 0. Also can check for silicates but I’d start with getting that ppm to 0 also make sure your getting a lot more easy wate then good water
We’ll what does the tds actually do from my understand it’s the minerals in the water which won’t have any effect on phosphates
 

Rjmul

NJRC Member
Bronze Member
We’ll what does the tds actually do from my understand it’s the minerals in the water which won’t have any effect on phosphates
Its total dissolved solids. It's a mystery. That could be dissolved phosphates, dissolved calcium, dissolved chlorine dissolved grahm crackers, dissolved ice cream. Anything.
 

nightmarepl

NJRC Member
Hmm interesting, i ordered new DI resin I’ll replace the one in my canisters

waiting on gfo to come in this week aswell and try to bring these phosphates to 0 should i hit it with anything to zero it out completely? Or let the gfo do it’s work
 

Mark_C

Staff member
Officer Emeritus
NJRC Member
Moderator
I dropped one of these in line with my RODI. Easy install and nice to be able to hit a button and see the TDS/ppm in and out of the unit.
Plus it lets you know when its time to start replacing filters.

 

Rjmul

NJRC Member
Bronze Member
Hmm interesting, i ordered new DI resin I’ll replace the one in my canisters

waiting on gfo to come in this week aswell and try to bring these phosphates to 0 should i hit it with anything to zero it out completely? Or let the gfo do it’s work
Don't let it zero out. What problem are you trying to solve here ?
 

Rjmul

NJRC Member
Bronze Member
Cyano ? Do you have enough flow ? I'm not totally convinced cyano is caused by high phosphates
 
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