Phosphates stuck at 0.2 in 5-month-old tank

[anthony1222]

I've been battling high phosphates since I set this tank up. My nitrates are 5-10 and I have a refugium with a big protein skimmer and just recently added a reefmat 500 to the tank. I've been dosing Phosphate-E for a few weeks now but it doesn't seem to do much. (Dosing near protein skimmer intake) I haven't harvested my chaeto yet since it's still small and growing really slowly, I'm guessing from lack of light. (I have an ecochic 8831) I have a red sea reefer 350 g2 with 1 foxface, 2 clownfish, 1 baby blue tang and a copperband butterflyfish. I feed 2 frozen PE mysis shrimp a day and a piece of nori.

I got tired of waiting for my phosphates to drop and pulled the trigger on my first coral which is a hammer.

Also would like to add that my rocks were previously used in an aquarium but has been bleached.

 

[CasperOe]

Seems you have suffocation filtration in that tank of yours and 0.2 isn't really that high. I would reevaluate the amount of nutrition (food, primarily) you're adding to your tank. Elevated phosphate don't come out of nowhere!

Have you tested your source water? Chances are that your source have high phosphates.

I have based my nutrient export on a large, well lit refugium. If you light it properly, it can be extremely efficient. Consider inviting in a good, powerful refugium light when you can. I am currently using 2 x Kessil A160 Tuna Flora.

 

[CasperOe]

 

[Mr. Mojo Rising]

.2 is not super sky high, my phosphate are at .1 sometimes goes to .15 if I'm not careful, it doesn't bother my tank. Soft and LPS and some SPS corals don't mind that level of phosphate at all.

Do you have algae in your tank? Or just concerned about the number? How is the hammer doing? Personally, I would just observe the hammer and see how it does.

if you feel you really want to lower it, then you will have better result with GFO and a reactor, it pulls the phosphate out. Whereas phosphate-e just lowers it, but it rises again later.

 

[exnisstech]

My most successful tank runs NO3 15ish and PO4 0.4 - 0.6. Maybe just step back and let it run to see where it settles in at. Some times trying to correct a problem that really isn't a problem can lead to more problems if that makes sense.

EDIT : I just remembered the title stated the tank is only 5 months old. I for sure wouldn't be too obsessed with chasing numbers even with live rock in it. All of my tanks seem to settle in and run at different nutrient levels, some higher some lower. If I were going to dose anything on a tank that young it would maybe be some bacteria like MB7 or zeobak. JMO

 

[Tired]

My vote, add some easy corals and run with it. Most corals will tolerate that level fine. Verify that you're feeding a good amount, then let it alone and see if it settles. If not, ah well- pick corals that don't mind.

 

[Randy Holmes-Farley]

Bleaching rocks won’t remove much phosphate. They may be part of the issue, but I wouldn’t worry about it now and I’d get the hammer.

 

[anthony1222]

Seems you have suffocation filtration in that tank of yours and 0.2 isn't really that high. I would reevaluate the amount of nutrition (food, primarily) you're adding to your tank. Elevated phosphate don't come out of nowhere!

Have you tested your source water? Chances are that your source have high phosphates.

I have based my nutrient export on a large, well lit refugium. If you light it properly, it can be extremely efficient. Consider inviting in a good, powerful refugium light when you can. I am currently using 2 x Kessil A160 Tuna Flora.

I have 0 tds coming out of my rodi filter

.2 is not super sky high, my phosphate are at .1 sometimes goes to .15 if I'm not careful, it doesn't bother my tank. Soft and LPS and some SPS corals don't mind that level of phosphate at all.

Do you have algae in your tank? Or just concerned about the number? How is the hammer doing? Personally, I would just observe the hammer and see how it does.

if you feel you really want to lower it, then you will have better result with GFO and a reactor, it pulls the phosphate out. Whereas phosphate-e just lowers it, but it rises again later.

I have green coraline algae growing on my glass and rocks right now but when the tank was newer it had a really bad ugly stage. Luckily that came and went and I no longer have any visible algae. I’m mainly concerned about the number since phosphates inhibits coral growth

I got the hammer yesterday and the polyps are all open and seems to be doing well so far

 

[CasperOe]

I have 0 tds coming out of my rodi filter

Ah alright, worth a shot i'd test it anyway just to eliminate one thing from the list.

 

[anthony1222]

Bleaching rocks won’t remove much phosphate. They may be part of the issue, but I wouldn’t worry about it now and I’d get the hammer.

I have 0 tds coming out of my rodi filter

I have green coraline algae growing on my glass and rocks right now but when the tank was newer it had a really bad ugly stage. Luckily that came and went and I no longer have any visible algae. I’m mainly concerned about the number since phosphates inhibits coral growth

I got the hammer yesterday and the polyps are all open and seems to be doing well so far

 

[anthony1222]

Bleaching rocks won’t remove much phosphate. They may be part of the issue, but I wouldn’t worry about it now and I’d get the hammer.

How long can rocks leech out phosphate for?

 

[DanyL]

How long can rocks leech out phosphate for?

It depends on either consumption rate of the tank inhabitants, by the export rate, and of course also how much is actually bounded in there.

The thing with PO4 is that it always strives to keep an equilibrium in a certain ratio between the rocks and the water - so when the levels in the water are getting lower, the rocks would leach more to compensate for it and reach the equilibrium once again.
(Probably not the best explanation, but hopfully enough for you to understand the concept).

 

[jda]

Aragonite do not leach and absorb po4, it binds and unbinds - there is a large difference. There are rules and stuff with binding and unbinding. The aragonite will not release more until the po4 level in the water column is lowered. If you never lower the water column level, the aragonite will stay in an equilibrium of sorts - what usually happens is that the water column level rises as you feed things and the rock/sand binds more.

 

[DanyL]

Aragonite do not leach and absorb po4, it binds and unbinds - there is a large difference. There are rules and stuff with binding and unbinding. The aragonite will not release more until the po4 level in the water column is lowered. If you never lower the water column level, the aragonite will stay in an equilibrium of sorts - what usually happens is that the water column level rises as you feed things and the rock/sand absorbs more.

I love how you started by stating it does not absorb, and ended up saying that it does lol

TBH I never knew there is any difference in these terms and thought they were equivalent in this context.

Mind explaining more about the difference?

 

[jda]

Touche... edited it, since it matters.

Thing of absorbing and releasing as a free for all that you cannot control. Binding and unbinding has methods of attachment (mollecular bonds in this case) and rules around the action.

In any case, there are rules with po4 binding to aragonite.

 

[Uncle99]

Some test kits can’t read phosphates below .2ppm.
I struggled with this for months until I got an ICP which said phosphates where 0.05ppm.
Bought the Hanna UL checker and it confirmed 0.08ppm.

What a waste of time and money in GFO, chasing a condition which did not exist.

 

[Lavey29]

5 month old tank will have unstable parameters still and phosphate is just one part. .2 is slightly elevated but nothing to even consider worrying about. It most likely can be lowered by cutting back pellet fish food and coral foods that always raise phosphate. You will not see much coral growth at 5 months because your biome is still developing. Just focus on weekly water changes and keeping numbers as consistent as possible. You want nitrates at 10 to 15 if you have a mixed reef.

 

[DanyL]

Touche... edited it, since it matters.

Thing of absorbing and releasing as a free for all that you cannot control. Binding and unbinding has methods of attachment (mollecular bonds in this case) and rules around the action.

In any case, there are rules with po4 binding to aragonite.

If understand it correctly - the difference between the terms are more to the way of attachment (forces), where one is a more general term while the other is subset of it?

Because even a sponge that absorbs water can theoretically be controlled to release an exact amount of, the attachment and release methods would be different however.

In the PO4/arragonite example the attachment/release is a chemical reaction on the other hand, but the concept is the same.

 

[DanyL]

If understand it correctly - the difference between the terms are more to the way of attachment (forces), where one is a more general term while the other is subset of it?

Because even a sponge that absorbs water can theoretically be controlled to release an exact amount of, the attachment and release methods would be different however.

In the PO4/arragonite example the attachment/release is a chemical reaction on the other hand, but the concept is the same.

I was close, but so found the answer.
Interesting, you always learn something new.

 

[jda]

I am sure that a real scientist can do better than I can with the term "rules."

It appears that aragonite can bind an nearly infinite amount of po4 - relative to our case. The more po4 that you add, the more that the rock can bind. It can bind a MASSIVE amount.

Imagine a sponge that would only absorb compared to the water volume that is present, or some other formula or rule. Sponges don't do that - they can absorb and release whatever they want whenever they want. You cannot get aragonite to unbind po4 unless you expose it to water with a lower po4 concentration, or dissolve the structure with acid. Because of these rules, aragonite can be a reservoir for po4 at high levels (in a bad way) and a buffer for po4 at low levels (in a good way - you likely will never get to true zero).

The reason to be precise with this in our case, is that people who thing that rock and sand can just let go of po4 for some unknown reason at any time are getting it wrong. This does not happen. If they think this, then they can think that the rock/sand is why their po4 is going up, which is not the case... so if they know, they can find the real reason, which is likely lack of export and possibly overfeeding.