How fast to reduce high PO4 levels in my tank?

[Mortie31]

Hi Chaps
A month ago I found out my ELOS phosphate test kit was misreading (or I'm colour blind) I had been getting a steady 0.08 for over 18 months using the kit, which I wanted, when the kit ran out I decided to go for a Hanna phosphurus ULR test kit instead.. Horror first test 0.3!!!! Subsequent tests and a check with a mates DD kit revealed it to be accurate. So I started to chuck rowaphos at the system, but I've lost 2 colonies in getting it down to 0.15 over a month, how long would you recommend to get it down to 0.06 ish without losing anymore colonies? Paradoxically I've never had algae in the tank but my cheato bed grows like stink, but I've always been disappointed with the colour of my sps.. Now I know why.. double check your kits chaps..
Cheers Paul

 

[plyle02]

Hi Paul,
In my experiences, I would say to go slow, the corals have adapted to increased nutrients, so reducing the phosphate too quickly will freak the sps corals out. As a general rule, corals that have deep brownish color usually indicate a higher than normal nutrients, conversely those exhibiting pale or bleached colors, usually indicate the lack of nutrients, a starved tank if you will. Taking a tank that is relatively high in nutrients to very low nutrients in short order is too much change and will likely cause death. So taking nutrients down slowly over time is probably the best approach, as nutrients go lower, the sps will begin to show original color, this is a good indicator for success. Numbers can fool you into making fast changes and making knee jerk reactions, trust me, I learn through experience, lol... Best of luck to you!

 

[Mortie31]

Thank you Perry, as a rough guesstimate how long a time frame are you thinking 3 months, 6 months? And any suggestions how you can control the rate, Im currently using about 2 cups of rowa in a reactor and its exhausting in about 10 days, but has brought the levels down 0.15 in 5 weeks, I'm guessing their will be some phos bound up in the rockwork as well. The systems net volume is about 750 L and is 3.5 years old, I'm patient so want to get it right.

 

[plyle02]

Paul,
I would use the corals as your compass. As long as they show no signs of necrosis, exhibit PE, and over all look healthy, do so, just pay attention to the details of the corals. You will know when PO4 gets low enough, your corals will start to show colors, usually evident in the tips. This process can take weeks, so if you are exhausiting media that quickly, I would suggest using 15-20% more media, again, adjust the flow using the ball valve to low, ramp up over several days until you resume to original flow that indicates the media tumbling. Yes, rock and sand can have laden nutrients that can take longer to exhaust, so this may take time to not just get there, but stay there. I cannot stress enough to let the signs of the corals tell you what is happening, a number is just that. BTW, are you testing during lit or non lit hours?

 

[Mortie31]

Once again thank you Perry, I only test during lit periods. I think your spot on about observing the corals, it's quite funny really I've merrily gone along thinking my levels were ok, but that the colours on my corals were not great, I've tried all the various colour potions out there, and it turns out to be a faulty kit, but as I've never had any horrible browning it's been frustrating but not a huge problem as growth has been great. My efflos are brown however my Horridas have great blue tips, my SSC is a great pink/ green and my slimmer is a great green colour. But none were as good as you see in other tank pics. I'll carry only with the Rowa as u recommend and keep a good eye on things, Is adding more media better than replenishing more often?
Cheers Paul

 

[Mortie31]

Here's a pic as of last month, sorry about the quality usual iPad pic

Paul