chemical substitution question

[Cnidoblast]

Can I use the dirt cheap sodium tripolyphosphate instead of the more expensive phosphate salts to raise available phosphate?

 

[BeejReef]

https://www.reef2reef.com/threads/trisodium-phosphate-dosing-math.354337/

https://www.reef2reef.com/threads/trisodium-phosphate.338431/

I don't know the answer, but had been researching the same thing very recently after using up a $10 bottle of phosphate in four days.

 

[Cnidoblast]

@Randy Holmes-Farley

 

[Cnidoblast]

https://www.amazon.com/Sodium-Tripolyphosphate-Super-Cleans-Grade/dp/B01JDX5ASQ/

If this would work it would be great since we can buy 10 lb at a time

 

[Dan_P]

Can I use the dirt cheap sodium tripolyphosphate instead of the more expensive phosphate salts to raise available phosphate?

No answer, just some doubts.

It is three phosphates joined together, like in ATP only without the A (that explanation is totally cryptic if you missed out on biology). Its used in detergents as a water softener by chelating magnesium and calcium and in food processing.

The conversion of polyphosphate to phosphate can be accomplished by algae. Can coral break it down? Another question is how do you propose to monitor the level of tripolyphosphate? How fast is consumed?

 

[Cnidoblast]

It is the tail end of ATP - as per measurement I haven't a clue - I might only dose a tiny amount

 

[Randy Holmes-Farley Verified Community Expert]

Can I use the dirt cheap sodium tripolyphosphate instead of the more expensive phosphate salts to raise available phosphate?

If it happens to be adequately pure, likely it is ok. If not, no. Do you want to experiment in this way?

 

[Randy Holmes-Farley Verified Community Expert]

https://www.reef2reef.com/threads/trisodium-phosphate-dosing-math.354337/

https://www.reef2reef.com/threads/trisodium-phosphate.338431/

I don't know the answer, but had been researching the same thing very recently after using up a $10 bottle of phosphate in four days.

You have a massive tank?

 

[Randy Holmes-Farley Verified Community Expert]

Is that really cheaper than ungraded tsp (sodium triphosphate)?

 

[Dkeller_nc]

In industry, sodium tripolyphosphate is used as an emulsifier, among many other uses. Randy's comment that "If it happens to be adequately pure, likely it is ok." is likely based on the fact that various reactions in a reef tank, whether by bacteria or inorganic, will break the tripolyphosphate down into simpler phosphates.

However, there are a number of potential undesirable side effects, one of which is that as an emulsifier, the STPP may cause your skimmer to go off-the-rails.

The bottom line is that monosodium phosphate (or trisodium phosphate) is extremely inexpensive - 2 lbs. of monosodium phosphate, food grade, can be had on Amazon for $21. So the bottom line conclusion is that even if you've got a swimming-pool sized tank, experimenting with STPP isn't going to save you a significant amount of money.

 

[Randy Holmes-Farley Verified Community Expert]

I actually think it won't impact a skimmer as it is not surface active. It binds cations like calcium, allowing other surfactants in detergents to do a better job.

I certainly agree there's no reason to try it anyway.

 

[BeejReef]

You have a massive tank?

It sure feels like it.. lol. I'm not certain what is going on. I have a pretty robust refugium relative to a pretty modest 65g DT. Still, it's just the center chamber on a sump that fits in the stand.
After a few months up, and of relatively smooth operation, I've zeroe'd P. I suspect rock stopped leaching. Nitrate rose from 4'sh to north of 60 over the course of maybe two weeks. Just started dosing trisodium phosphate (food grade) and have pulled N back down to 30... and falling.

The P consumption is way beyond what I ever could have expected though. Not exaggerating, I can dose it up to roughly .4 late in the evening. 24 hours later, I'll read low but detectable (.03-.06). I try to time the dose so the whites aren't on in the DT during the highest levels.

Every .3-.4 of P consumed seems to drop my N another 10-15, very roughly speaking. Hanna LR (not ULR) and R.S. Also, I do not run a skimmer.