Phosphates from calcium reactor

[Yarm79]

Ok so as my ongoing phosphate problem persists, I thought I would do a test on the 3 reactors on my tank with my Hanna Phosphorous meter.

Tank water read 24 = 0.07
This is disappointing as Iv changed 20% water this week and it was 28 before I started.
I tested my phosphate reactor it read 7 = 0.02 happy with that
I tested my carbon reactor it read 11 = 0.03 happy with that
I tested my calcium reactor effluent it read 18 = 0.055 so not so happy with that.
I am using ARM media. Any advice how to counter this as I'm guessing that's where most of my phosphates are coming from :rolleyes:

[Randy Holmes-Farley]

0.055 ppm in the reactor effluent? I don't understand. That's lower than the tank water (0.07 ppm).

Even if it were a little higher, it is probably not your biggest source.What is the flow rate per day relative to the tank volume?

The flow is likely so low that you end up adding only a small amount of phosphate to the water, while a single feeding will add much more phosphate.

I discuss that in this article:
Phosphate and Math: Yes You Need To Understand Both
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.

The same sort of calculation applies to analyzing other phosphate issues, such as the GAC in scenario three. The issue of finding "high" phosphate in GAC soaked in fresh water was frequently quoted as a reason to use one or the other brand of GAC, and probably still is. But simple analysis as shown above for the food rinsing puts the lie to this being a big problem.

One needs to consider how much GAC one will really use in the aquarium and how often it is added in order to interpret how important the added phosphate is. A typical recommendation might be 1 cup of GAC per 100 gallons of aquarium water, and to change it in 4-6 weeks. Let's assume we detect 0.5 ppm phosphate when a teaspoon is placed in a cup of water, and we get scared by the dark blue color during the test. Is this reasonable? That 0.5 ppm from a teaspoon in a cup of water translates to 0.015 ppm phosphate when a cup is used in 100 gallons.

That 0.015 ppm may be significant, being a typical target concentration level for reef aquaria and amounting to about half to a twentieth of the amount added daily in foods, but remember, it is used for 4-6 weeks. During those 4-6 weeks before the next replacement, foods add 50-700 times as much phosphate. So while it is not unreasonable to look for another brand of GAC, to blame phosphate or algae issues in the aquarium on its use would stretch credibility because it is a very tiny portion of the total phosphate being added.

[Yarm79]

Thanks for the reply Randy
I'm possibly clutching at straws trying to find why no matter what I cannot get my tank water phosphates under 0.07, that being the lowest I can get it!
As above I tested all my reactors to see if there was a problem somewhere and the calcium reactor had the highest reading.
I use a phos ban reactor half full of Rowa Carbon not sure if this is overkill, but as above the reading from the carbon reactor was pretty low in 0.03.
I feed one a day on an evening usually mysis RS. I pour the water put before adding the food to the tank.
Tank is 210 US gallon, 1 blue throat trigger, 2 yellow tangs, 2 banana wrasse (pretty small) 2 cardinals, 3 anthias, cleaner wrasse, flame angel. I don't really consider that a lot of fish. Nitrates are zero and tank has good circulation. I was wondering whether to add more clean up crew? I am also for the first time in five years suffering from hair algae :(

[Art13]

I would bet a clean up crew anyways, i don't know if any of your fish will pick on them though as i've never looked into a trigger or banana wrass or cleaner wrasse. i did snails and left out hermits as they tend to attack the snails. all in what you want though. How old is your tank? its possible the phosphate is coming from your rocks and/or sand and will continue until it balances out, just have to ride it out.

[Yarm79]

Tank rock etc been running 5 yrs

[tkeracer619]

Sounds like it is leaching from your rock.