Nitrates phosphates and dosing question(s).

RANDY! Phosphates coming out of RO/DI looks like are about .04-.08. I tested twice. Should I replace all filters and membrane? Membrane is 10 months old. Was unsure if the membrane was responsible for nitrates. DI is changing color and was already part of my order I am placing tomorrow morning. Phosphates in tank are .08 tonight after a 5g water change. I am also debating on getting a Hanna checker? I am reading 0 TDS which doesn't sound right if I have phosphates
 
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The membrane is most likely responsible for the phosphates. .04-.08 is less then 1ppm TDS if there is nothing else in the water. Also your test kits can have some variability, honestly I wouldnt worry to much about your levels in your tank they are both plenty low enough for SPS as they are, as long as your lighting and flow are adequate.
 
well I am fighting Cyano so I want the lowest phosphates possible. So I think I am gonna replace all filters, membrane, di, install a dual TDS meter(i do have handled), gonna get a hanna checker for phosphates then I can see in digital what my PO4 is
 
and ya know looking at the Hanna Checker it says •Precision: ±0.04 ppm (mg/L) ±4% of reading @ 25°C so is it really worth it?
 
Something else i just thought about is there a difference in test kits between saltwater and freshwater? Should i just buy a hanna and see what that reads then replace filters or jist bite bullet and buy new filters and hanna checket?
 
The Hanna Phosphorus ULR Checker isn't rated for freshwater use. The other Hanna phosphate checkers should be okay.
 
kissman said:
RANDY! Phosphates coming out of RO/DI looks like are about .04-.08. I tested twice. Should I replace all filters and membrane? Membrane is 10 months old. Was unsure if the membrane was responsible for nitrates. DI is changing color and was already part of my order I am placing tomorrow morning. Phosphates in tank are .08 tonight after a 5g water change. I am also debating on getting a Hanna checker? I am reading 0 TDS which doesn't sound right if I have phosphates
Click to expand...

That's no concern at all. It is so much less than you feed every day (maybe 100 times less) that it is not important, even if it is accurate. :)

I discuss it here:

Phosphate and Food
http://www.advancedaquarist.com/2012/3/chemistry

from it:

Comparison of Food Sources of Phosphate to Other Sources
What about other sources of phosphate, like the "crappy" RO/DI water containing 0.05 ppm phosphate? A similar analysis will show it equally unimportant relative to foods.

Let's assume that the aquarist in question adds 1% of the total tank volume each day with RO/DI to replace evaporation. Simple math shows that the 0.05 ppm in the RO/DI becomes 0.0005 ppm added each day to the phosphate concentration in the aquarium. That dilution step is critical, taking a scary number like 0.05 ppm down to an almost meaningless 0.0005 ppm daily addition. Since that 0.0005 ppm is 40-600 times lower than the amount added each day in foods (Table 4), it does not seem worthy of the angst many aquarists put on such measurements. That said, tap water could have as much as 5 ppm phosphate, and that value could then become a dominating source of phosphate and would be quite problematic. Purifying tap water is important for this and many other reasons.
 
Ok then i am going to just replace the di since i still show 0 tds. i did crank me gfo way down to see if i can get 0 po4 coming out. I will be out of town till Monday but will test the reactor again and see what its doing. I think i wanna find a freshwater phosphate test kit then i can accuratly test ro/di water. I will continue to ramp vinegar to 12 amd see how things look. In the meant time water coming out of reactor reading 0 is what i will work on
 
Why replace the DI? A new one probably won't be any different if you are at 0 ppm TDS. There's no need to replace it.

Don't get obsessed needlessly on traces of phosphate in top off water which may not even be accurate. :)
 
It has changed color over 1/2 to 3/4 of it. So its time the stuff is cheap and i like to change it before i get tds
 
hey Randy I am at 14ml dosing. Tomorrow I am setting up my vinegar on a doser. Is it best to do spread the doses out of twice, three times or 6 times a day? I will up my dosage tomorrow as well.
 
Lots of people dose only once a day, even with large doses. That said, if it's easy enough, I'd likely spread the dosing through the hours when the lights are on.
 
i am winning the battle! still growing on pwerheads some
before

photo-M.jpg


after


1st-month-of-Kalk-M.jpg
 
That's looking good. It's always good to compare photos...makes you feel better actually seeing the difference.
 
thanks its looking better but i am not there yet, I wanna get rid of most of the softies and get some SPS going
 
Hey Randy quick question. I just got more GFO in from BRS. I got the high capcity this time. Do you recommend I continue to run duble the amount and run 1 cup instead of the half a cup it call for? I am still running 2 cups of the reg GFO
 
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