Confused by Rowaphos

Joe Batt · May 14, 2018

Just seen this post, I have the exact same problem and literally 30 minutes after changing the ROWAPHOS. Re-tested with same result, tank water Po4 is lower than the reactor outlet.....I am using a Hanna ULR Phosphorus tester.

Randy Holmes-Farley · May 14, 2018

Joe Batt said:
Just seen this post, I have the exact same problem and literally 30 minutes after changing the ROWAPHOS. Re-tested with same result, tank water Po4 is lower than the reactor outlet.....I am using a Hanna ULR Phosphorus tester.

What values do you get?

Joe Batt · May 14, 2018

I had 60 ppb Phosphorus / 0.184ppm Phosphate in the tank and then around 30 minutes after I refilled the reactor I tested the outflow and it was giving 70 ppb Phosphorus/0.215 ppm Phosphate. I retested with exactly the same results.

I have turned the flow down to see if that makes any difference. The flow was originally registering as 181 ltrs per hour and now its 95 litres per hour. Will retest in 30 mins. Just very strange, even if the flow was too high and not giving the ROWA time to absorb any Po4 I don't understand how it could have gone up.

It was fresh new box of Rowa as well.

Joe Batt · May 14, 2018

Ignore me.....I have used the wrong reagent .....I used the Nitrite reagent not Phosphorus

Randy Holmes-Farley · May 14, 2018

lol

OK.

Joe Batt · May 14, 2018

I astound myself with my own stupidity at times .....

griff500 · May 14, 2018

lol

Well my results aren't down to that!

I've posted another thread to get some ideas on flow rate through the reactor.

Even though the measured levels don't appear to be particularly improving I have noticed definite improvements in the appearance of corals, more polyp extension and significant visible growth since using Rowaphos, so it's doing something.

griff500 · May 19, 2018

Out of curiosity I almost doubled the amount of Rowaphos in the reactor yesterday. Today (in the morning - I usually measure levels at 8pm) phosphates in the display measured 0.3... Reactor output at the same time was 0.15.

So the more I try to remove phosphate the higher the reading I seem to get in the display. I'm guessing this is just a reflection of the amount that has been bound up in rock and substrate?

Randy Holmes-Farley · May 19, 2018

griff500 said:
Out of curiosity I almost doubled the amount of Rowaphos in the reactor yesterday. Today (in the morning - I usually measure levels at 8pm) phosphates in the display measured 0.3... Reactor output at the same time was 0.15.

So the more I try to remove phosphate the higher the reading I seem to get in the display. I'm guessing this is just a reflection of the amount that has been bound up in rock and substrate?

I wouldn't expect a rise from that, but it is a big reservoir that can take a long time to deplete.

griff500 · May 20, 2018

Ok, so I'm not feeding differently or doing anything different other than increasing the amount of Rowaphos. I measured at the usual time this evening and I was getting around 0.3 in the tank and from the output.

The more I try to lower phosphate the higher the reading I'm getting...

Randy Holmes-Farley · May 20, 2018

griff500 said:
Ok, so I'm not feeding differently or doing anything different other than increasing the amount of Rowaphos. I measured at the usual time this evening and I was getting around 0.3 in the tank and from the output.

The more I try to lower phosphate the higher the reading I'm getting...

lol

Maybe you bought someone's used Rowaphos.

Greenstreet.1 · May 20, 2018

This is weird I have been using rowa for years and never seen this happen. Right now the rowa in the reactor is over two months and still lower than the tank.

griff500 · May 20, 2018

lol, I'd have hoped to pay a lot less if it was used Randy.

It is utterly bizarre and extremely frustrating. I changed the Rowaphos and the output is now half of what is in the tank, but that's still a 0.15 output, which is what I had in the tank before I started 'fixing' the issue.

griff500 · May 22, 2018

Now it all makes sense...

Apparently multiple rinses with RO water is not enough to get the vial completely clean, resulting in higher readings.

The Rowaphos has done it's job... surprise surprise...

teller · May 22, 2018

griff500 said:
Now it all makes sense...

Apparently multiple rinses with RO water is not enough to get the vial completely clean, resulting in higher readings.

The Rowaphos has done it's job... surprise surprise...

How are you rinsing your vials now, may I ask you?
Thanks

griff500 · May 22, 2018

I was rinsing using RO and tank water - putting water in, shaking vigorously, repeating probably 3 or 4 times.

I've ordered some new vials (cuvettes?) and I'll see what results I get with those. I'll also try to sterilise the existing vials and see what readings I get.

I tested yesterday with a vial that had completely dried out and got a reading of 10 (0.03). My girlfriend laughed at my obvious joy and told me to test again. I got 60... tested again and got 80... She was rather amused... me, not so much...

I tested a reference solution that should be 0.08 and got 90 (about 0.27). Tried my Red Sea kit and got the light yellow (almost clear) colour and also confirmed the reference solution at 0.08, so I knew the Red Sea kit was giving a correct reading. I then thoroughly rinsed the vial and used a cotton bud on the inside and it came out blue. I then used some tissue paper inside and it still came off blue. Obviously no amount of rinsing was getting it completely clean.

Perhaps after using the vials for quite a few years they are no longer capable of being cleaned properly or they need to be sterilised.

tastyfish · May 22, 2018

Well that's interesting. I might need to change my cleaning method as I usually rinse with tap water then with RO, taking and emptying 3 times before doing the test.

PS: I've used Rowa for years and never experienced it leaching back, the reactor output has always been lower than the display, although the biggest impact on levels is immediately as the smaller particles seem to have the biggest impact, but exhaust rapidly.

griff500 · May 22, 2018

I had previously cleaned in the same way as you - tap water and then RO (or tank water) and I seemed to get quite consistent results. After doing that, try cleaning the inside with a swab and see if it comes off blue.

Greenstreet.1 · May 22, 2018

This is interesting will have to check mine.

griff500 · May 23, 2018

I received new cuvettes for the Hanna checker. Checked the tank water and got a measurement of around 0.13 - not really any different to the old cuvettes, aside from one outlier result that was what I was expecting. Checked with the Red Sea kit and got a very pale yellow, which should be fairly close to undetectable (not quite what I want but possibly better than 0.13).

If I use the kits with a reference solution the Red Sea kit appears to give a correct reading that matches the reference solution. The Hanna checker consistently gives a reading of around 3 times what the reference solution is supposed to contain.

Annoying.

I have another box of reagents that I can try, although they might be from the same batch.