Do you REALLY need to test for Phosphates?

C-21 USAF

New member
I've read so much about this. Some say you can't really test for PO4, that tests don't show actual levels.

Some judge their levels by looking at their tanks inhabitants.

What say you?
 
Fair question.
IMO, It depends on the type of tank and how long it has been running.

For SPS tanks…. bear with me….

The only two things I check regularly are temp- maybe twice a day and Alk, every few days… I run a calcium reactor, so the big three are dosed in some proportion. If Alk stays around 8, then ca and mag will be within some acceptable limit and small drifts are of no consequence. I don't check ca or mag anymore.

Moving to nutrient levels. When I first set up, I checked nitrate and phos weekly.
Eventually, when SPS started growing and colouring up, I knew levels were low.
Now, I change a fixed amount of GFO monthly without fail, without checking levels and I harvest macro algae monthly without checking nitrate levels.

If my coral tips are still bright, then I know my levels are fine.

If I chase a lower phos or nitrate level, then I know I will upset something in the tank and pay for it!….. So, as long as corals look happy, tips are colourful and the polyps sparkle, then I know my levels are good. If I chase zero—— I will pay for it!.

If my glass needs cleaning more than twice a week, then I know my GFO needs an early change. The frequency of cleaning glass is different for different tanks. I have a smaller tank linked to my big tank, that is very narrow and light falls on both front and back glass- it has the same water as my big tank and needs cleaning EVERY DAY. But I still know if the algae gets thicker, then my GFO needs changing.

Bottom line- the more mature the tank, the less you need to test!.
Phosphate testing in non-essential in clean, stable running tanks.

http://www.reefcentral.com/forums/showthread.php?t=2073747&page=25


Mo
 
Fair question.
IMO, It depends on the type of tank and how long it has been running.

For SPS tanks…. bear with me….

The only two things I check regularly are temp- maybe twice a day and Alk, every few days… I run a calcium reactor, so the big three are dosed in some proportion. If Alk stays around 8, then ca and mag will be within some acceptable limit and small drifts are of no consequence. I don't check ca or mag anymore.

Moving to nutrient levels. When I first set up, I checked nitrate and phos weekly.
Eventually, when SPS started growing and colouring up, I knew levels were low.
Now, I change a fixed amount of GFO monthly without fail, without checking levels and I harvest macro algae monthly without checking nitrate levels.

If my coral tips are still bright, then I know my levels are fine.

If I chase a lower phos or nitrate level, then I know I will upset something in the tank and pay for it!….. So, as long as corals look happy, tips are colourful and the polyps sparkle, then I know my levels are good. If I chase zero—— I will pay for it!.

If my glass needs cleaning more than twice a week, then I know my GFO needs an early change. The frequency of cleaning glass is different for different tanks. I have a smaller tank linked to my big tank, that is very narrow and light falls on both front and back glass- it has the same water as my big tank and needs cleaning EVERY DAY. But I still know if the algae gets thicker, then my GFO needs changing.

Bottom line- the more mature the tank, the less you need to test!.
Phosphate testing in non-essential in clean, stable running tanks.

http://www.reefcentral.com/forums/showthread.php?t=2073747&page=25


Mo

Love this post. I'm almost there. Occasionally If something goes a little wacky I'll test more often. What Mo says is dead on, but he obviously knows what he is doing. Not necessarily what a beginner should be doing. I use my bonsai as my phosphate meter. When the base starts to brown out, it's time to change gfo. Only thing I check is Alk a few times a week and salinity right before wc. If things seem off, I may test phos and nitrate occasionally. Mag gets tested once in a blue moon, cal even less.
 
I have always tested every week since starting to keep SPS since 93. I keep a log on the tank to give me feedback on how the tank is doing I run all the test's As I am always learning about the care of coral's. One must watch trends of uptake to know what the tank is needing each week. But no if you don't want to you don't have to do anything just watch the tank till problems occur that you can not "fix" fast. The only that happens fast in a reef tank are bad things.
 
Love this post. I'm almost there. Occasionally If something goes a little wacky I'll test more often. What Mo says is dead on, but he obviously knows what he is doing. Not necessarily what a beginner should be doing. I use my bonsai as my phosphate meter. When the base starts to brown out, it's time to change gfo. Only thing I check is Alk a few times a week and salinity right before wc. If things seem off, I may test phos and nitrate occasionally. Mag gets tested once in a blue moon, cal even less.

You're right about salinity too, but unless you use a lot of water for dipping etc and you have auto top off, it's usually fairly constant.

If you're a beginner and your tank is new, test a lot until it becomes stable.
Again, phosphate/ nutrients eventually will drop if you stick to a religious routine with everything you do. Change GFO monthly, just work out how much you need.

Mo
 
Mo, my current tank is only 30 gal. That said, I'm religious with my routine, so tank is on cruise. I only check alk because that one tends to change quickly in a small tank packed with sps.
 
Fair question.
IMO, It depends on the type of tank and how long it has been running.

For SPS tanks…. bear with me….

The only two things I check regularly are temp- maybe twice a day and Alk, every few days… I run a calcium reactor, so the big three are dosed in some proportion. If Alk stays around 8, then ca and mag will be within some acceptable limit and small drifts are of no consequence. I don't check ca or mag anymore.

Moving to nutrient levels. When I first set up, I checked nitrate and phos weekly.
Eventually, when SPS started growing and colouring up, I knew levels were low.
Now, I change a fixed amount of GFO monthly without fail, without checking levels and I harvest macro algae monthly without checking nitrate levels.

If my coral tips are still bright, then I know my levels are fine.

If I chase a lower phos or nitrate level, then I know I will upset something in the tank and pay for it!….. So, as long as corals look happy, tips are colourful and the polyps sparkle, then I know my levels are good. If I chase zero—— I will pay for it!.

If my glass needs cleaning more than twice a week, then I know my GFO needs an early change. The frequency of cleaning glass is different for different tanks. I have a smaller tank linked to my big tank, that is very narrow and light falls on both front and back glass- it has the same water as my big tank and needs cleaning EVERY DAY. But I still know if the algae gets thicker, then my GFO needs changing.

Bottom line- the more mature the tank, the less you need to test!.
Phosphate testing in non-essential in clean, stable running tanks.

http://www.reefcentral.com/forums/showthread.php?t=2073747&page=25


Mo

I agree mostly. I only check alk on a regular basis. I do check ca once in a while, like every month or 2, just because it can change but seldom does in my system. I have had it go very high though to the point of causing problems but that was at the beginning stages & due to not testing what I was dosing.

I never test mg because a: it has to be in good range in order for ca to be in good range and b: because my test kit dried up.

I test po4 & no3 even less. I really think these are credited for too many problems where other things are the real cause. My po4 was 1.03 on my last check with no issues on my sps. Although that's a bit higher than I generally keep it, I still generally run with it higher than most people. I have about 50 different acros.
 
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I don't run GFO, I don't dose carbon (anymore), but I do run a small algae scrubber. I feed my SPS daily and I test PO4 every two weeks to make sure I keep it low, but not ZERO. I aim for 0.02 ppm PO4 (Milwaukee Martini MI-412 PO4 colorimeter).
 
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