Aragonite Sand And Phosphate Adsorption

[t5Nitro]

@jda would you recommend matching a high phosphate system when transferring to a new tank with new aragonite sand and previously no sand in the old system? I'm going from a high nutrient system that has run phosphate to 0.5-0.7 ppm to a new system that I'm now trying with aragonite sand. Wondering if I should at least dose up to 0.1ppm or so before adding the coral over. I might have to dose quite a bit if absorbed by all the sand.

 

[Dan_P]

Does dilute acid mess around with phosphate tests? Say testing the sample before and after acidification.

Edit - to clarify I’m not talking about regenerating sand, more obtaining total adsorbed phosphate concentrations.

I‘m wondering if the goal would be to use only enough acid to dissolve a tiny fraction of the sand, say <0.01%. This way, the wash water will be neutralized and the dissolution will be limited to the sand grain surface. I am thinking in terms of mixing the dilute acid in a beaker or bucket. All bets are off if you are washing a column of calcium carbonate with acid.

 

[taricha]

I‘m wondering if the goal would be to use only enough acid to dissolve a tiny fraction of the sand, say <0.01%. This way, the wash water will be neutralized and the dissolution will be limited to the sand grain surface. I am thinking in terms of mixing the dilute acid in a beaker or bucket. All bets are off if you are washing a column of calcium carbonate with acid.

Does distilled water fit your criteria for dissolving a small amount of aragonite and then stopping? And allowing fairly quick simple po4 transfer off the sand grains?

 

[Dan_P]

Does distilled water fit your criteria for dissolving a small amount of aragonite and then stopping? And allowing fairly quick simple po4 transfer off the sand grains?

It might. Just need some data now.

 

[billyocean]

I am going to transfer my current tank to a new tank soon (125 to 240 kr 300 gallon). I will be keeping the liverock and adding somw more sourced LR but going with new pre-rinsed sand. Currently I am dosing 23 ml per day of phosphate to keep my po4 at .07ish. After reading through this it brings me to this question. When starting a new tank with new pre-rinsed sand which will be aragaonite special grade (unless there are any better suggestions)...should I run it with sand only for a bit and keep adding phosphate so it somewhat levels out before transferring? I guess what I'm trying to articulate is; with the transfer and new sand is my phosphate going to be swinging wildly for a while? I do I understand constant testing/monitoring and the fact that my water volume being higher along with other things will obviously be factors. In the end will my area of thought process on this even matter or should it be a run with it and test heavy (which I will anyways) situation. Thanks to the great minds that have put in the time and effort behind this test.

 

[Dan_P]

I am going to transfer my current tank to a new tank soon (125 to 240 kr 300 gallon). I will be keeping the liverock and adding somw more sourced LR but going with new pre-rinsed sand. Currently I am dosing 23 ml per day of phosphate to keep my po4 at .07ish. After reading through this it brings me to this question. When starting a new tank with new pre-rinsed sand which will be aragaonite special grade (unless there are any better suggestions)...should I run it with sand only for a bit and keep adding phosphate so it somewhat levels out before transferring? I guess what I'm trying to articulate is; with the transfer and new sand is my phosphate going to be swinging wildly for a while? I do I understand constant testing/monitoring and the fact that my water volume being higher along with other things will obviously be factors. In the end will my area of thought process on this even matter or should it be a run with it and test heavy (which I will anyways) situation. Thanks to the great minds that have put in the time and effort behind this test.

Just thinking out loud after recent email exchange with @taricha.

We know when a new aquarium is set up with new aragonite sand and rocks, it takes time before phosphate stops bottoming out. Why aren’t we pre-saturating the new aragonite sand with phosphate? For example, if your ideal phosphate level is 0.03 ppm, saturate the sand at 0.03 ppm before putting it into the aquarium.

 

[billyocean]

Just thinking out loud after recent email exchange with @taricha.

We know when a new aquarium is set up with new aragonite sand and rocks, it takes time before phosphate stops bottoming out. Why aren’t we pre-saturating the new aragonite sand with phosphate? For example, if your ideal phosphate level is 0.03 ppm, saturate the sand at 0.03 ppm before putting it into the aquarium.

Thank you! Seems like it would make sense to saturate to a level to match the saturation of the water level for a bit of equilibrium. Perhaps this may keep any swings to a smaller margin until things can level out over time.

 

[jda]

New tanks set up with used rocks, or dead/dry rock, usually have no issues with po4 being too low. Fresh ocean rock, maybe since it came from an environment with perhaps less than 1 ppb of po4... however, most cycle/cure this rock and after the die off, there is some po4 that does get bound to the rock from the dead organics making it through part of the N cycle.

I have well documented, that I keep my reef at 1 to 3 ppb of po4, which I believe is best and most like NSW. I don't have any cyano, diatoms or dinos to growth limit with higher po4, so that is no issue for me - yes, raising po4 and no3 poisons those things and does not do what most people on the long threads think that it does. Honestly, just a trace or po4 fine and I would focus more on biodiversity, microfauna and stuff. Most of that biodiversity is quite sensitive to higher po4 levels and if you kill it, you have to order new rock/sand/whatever to get it back.

Availability > residual for both po4 and no3. Feed heavily and export heavily with massive availability but low residuals. Of course, you cannot test for any of these, so more experience is required to know what is going on.

If anybody want to "add" phosphorous (which is the goal, not phosphate), why add just inorganic phosphate on the back end by dosing, instead of adding more forms by just feeding your fish more and having lower export for a short time? I cannot stress this enough, but we don't have any idea if the inorganic po4 that we test for is useful for most things, if it used as a secondary source with energy costs, or whatever. All that we know FOR SURE is that higher levels can kill sensitive inverts, matting bacteria, micro/macro algae, some coral and can inhibit calcification. The gradient of decline is different for every organism, which also makes this hard - I have acropora that suffer at .1 ppm po4 and others that would be just fine at 1.0 ppm.

Lastly, I would not chase po4 without a Hannah Ultra Low. The other test kits are not good enough to make a solid decision.

 

[jda]

This is off topic, but to bring this full circle in hopes of clarity, when true coral gets too hot and expel all of their zoox in a bleaching event, they also expel a great majority of the building blocks that they often spent a lifetime capturing - this includes phosphorous. This is one reason that it is SO hard for them to recover since they are more fit for incremental capture and recycling rather than mass additions.

You have to ask yourself what your goals are. If you want to keep any coral at any time, have sensitive inverts, have snails, urchins, etc. spawn, and all of that, you are going to need to keep your po4 close(r) to ocean levels but also have other forms of available phosphorous - this is also in the super optimal growth zone. If you want some corals that are less sensitive and to keep dinos, diatoms and cyano at bay, then you can raise the level until the nasty stuff dies back. There are many levels in between and beyond. There is no right or wrong here. It is easier to keep the less sensitive things and costs less. I even keep my current FOWLR at no more than 5 ppb of phosphate since I like the coralline to cover everything and keep any hair algae at bay - the front glass can completely get covered in a few weeks with a Home Depot LED shop light over the tank and I have to add calcium and carbonate to a FOWLR just for this.

Unless you have an acute understanding of your goals and how phosphorous and phosphate are not the same thing, how the interact in the tank, etc., I would not add anything additional to your tank since you might have to work plenty hard to get it out one day. If you know what you want, then have at it.

 

[t5Nitro]

Any issues taking coral from a phosphate 0.7 ppm tank to a 0.06 ppm new tank? Or is this more relief for them to get out of that old environment.

 

[Garf]

LOL;

Build Thread - Garfs SPS cube

Lookin good mate! Are you worried about the rust particles upsetting your tank etc?

www.reef2reef.com

 

[Randy Holmes-Farley]

Just thinking out loud after recent email exchange with @taricha.

We know when a new aquarium is set up with new aragonite sand and rocks, it takes time before phosphate stops bottoming out. Why aren’t we pre-saturating the new aragonite sand with phosphate? For example, if your ideal phosphate level is 0.03 ppm, saturate the sand at 0.03 ppm before putting it into the aquarium.

That seems sensible, but it may or may not work if the fresh sand also precipitates a bit of calcium carbonate on top of it. Sand hardening when new would seemingly be evidence of that process run to a higher than typical extent.

 

[Randy Holmes-Farley]

Any issues taking coral from a phosphate 0.7 ppm tank to a 0.06 ppm new tank? Or is this more relief for them to get out of that old environment.

Could be, yes. It may take time for the corals to ramp up phosphate uptake capability.

 

[Dan_P]

That seems sensible, but it may or may not work if the fresh sand also precipitates a bit of calcium carbonate on top of it. Sand hardening when new would seemingly be evidence of that process run to a higher than typical extent.

Sure, all true.

Wouldn’t the magnitude of surface area direct you towards saturating the tens of kilos of sand with phosphate and not worrying about the gradual accumulation of just grams of new calcite? Or am I not understanding your idea?

 

[Randy Holmes-Farley]

Sure, all true.

Wouldn’t the magnitude of surface area direct you towards saturating the tens of kilos of sand with phosphate and not worrying about the gradual accumulation of just grams of new calcite? Or am I not understanding your idea?

My thought is that it only takes a small amount of CaCO3 to smother the intentionally added phosphate, but I cannot say for sure that such a thing will happen and I agree that preconditioning new rock and or sand (up or down) before use is a good idea.

 

[Dan_P]

My thought is that it only takes a small amount of CaCO3 to smother the intentionally added phosphate, but I cannot say for sure that such a thing will happen and I agree that preconditioning new rock and or sand (up or down) before use is a good idea.

I had sub micron calcite crystals in mind not covering much, maybe bridging sand grains

 

[Garf]

Once again, 2.5grms ish of old sand,I replaced the water with fresh saltwater, 20 mls, occasional stir, waited 10 days since last test, same result, somewhere between 0.03 and 0.1ppm (salifert). In summary, this is the third de-adsorption, 10mls (0.25ppm), 20mls (0.03-0.1ppm), 20mls (0.03-0.1ppm).

Once again, 2.5grms ish of old sand,I replaced the water with fresh saltwater, 20 mls, occasional stir, waited 8 days since last test, result 0.20 Hanna. In summary, this is the fourth (and final, as it turn out) de-adsorption, 10mls (0.25ppm), 20mls (0.03-0.1ppm), 20mls (0.03-0.1ppm), 20mls(0.20 Hanna LR).
You may recall my wife being a very efficient cleaner upper? Yep, chucked my sample in the bin, end of this particular test. Good job she makes a lovely curry

 

[Garf]

First full week of low level dosing (0.2 ppm per day) on sand that’s already been exposed to 22ppm phos (6 litres water, 2kgs calcite sand), I’m getting a regular reading of 0.2 ish ppm (salifert), so in my book it must be consuming around 0.2ppm per day.

I’ve not tested this bucket for 3 weeks, been low level dosing but now tested with Hanna after 26ppm ish, 6 litres water, 2 kgs calcite, Hanna FLASHING 2.50ppm, lol. I guess the sand is full after additions for 3 months

 

[Garf]

Would Lanthanum in a remote regeneration bucket pull a lot of phosphate off the calcium carbonate? Then rinse (or filter out) to remove lanthanum precipitation. If so I’m guessing the really cheap stuff would suffice as it’s not going in the tank anyhow. In particular thinking about removing the fluidised sand filter in its entirety from the tank, plopping in a bucket, running with an excessive amount of cheap Lanthanum, rinsing in RODI, replacing on the tank. If the adsorption / desorption is as fast as it appears, multiple runs could be made in short order if required.

 

[jda]

I use SeaKlear pool LC to take phosphate out of rocks in bins. Works great. You can be fast if you want since there are no inverts to worry about. You need to use socks and/or a skimmer to remove as much as you can.

It can take many months to get all of the po4 out, which is my goal. However, you can get the stuff near the surface done pretty quickly. Lots of flow is a good idea.

AFAICT, LC is LC... no need to buy the stuff made for reef tanks. The pool stuff is really strong and goes a long way, so dilute it or be smart if you use it in a tank with inverts.