Dosing of PO4 and traces apart

[PeterGwee]

Hi folks, some good info on dosing this 2 stuff. Try to dose them a couple of hours or a day apart to prevent possible precipitation issues.

Regards
Peter Gwee

[juggler]

Really? How do I tell that that has happened?
What does PO4 precipitate with in the traces?
What about the PO4 in fish food/waste?

Thanks.

[PeterGwee]

Its Fe and PO4 that will precipitate out of the solution. Tom Barr mention it quite a couple of times in various forums and BarrReport website so I think it might be useful for folks here.

KF,
1) You might want to do it in a with a glass of water with Fe and KH2PO4 or any PO4 source added. Observe what you see after that...might be quite tough to see it in a tank though. (It occurs only in a high aerobic condition in which a planted tank is.)

2) Fish food don't usually have high PO4...its more of NO3. Which is why I think we should dose PO4 as our tap is pretty lean in it as well.

Regards
Peter Gwee

[vinz]

Hello, can speak english or not?

Just kidding, but it is a little vague...

What's will happen?
- PO4 causes Fe to precipitate,
- Fe cases PO4 to precipitate,
- Both precipitate in separate compounds, or
- As a single compound?

I'm guessing it's the last one.

I suppose this renders both useless to plants? Will they dissolve back into solution eventually?

[PeterGwee]

Huh?

Read this

It might not happen in our tanks but its better to be on the cautious side and dose them apart for at least a couple of hours.

Regards
Peter Gwee

[|squee|]

I've read that some people experience a slight cloudiness after they dose traces too. Guess that's why they say dose macros and mircos on different days.

[Rupert]

My simple test was to mix a small sample:

1 LushGro Micros + KH2PO4 = cloudy precipitate
2 LushGro Macros + KH2PO4 = cloudy precipitate
3 LushGro Macros + LushGro Micros = solid precipitate

Try it and I am sure you will be as surprised as I was on how cloudy precipitate was from 1& 2. I poured the few mls back into my tank, which probably wasn't a good idea at the time.

However I would like to know the answer to questions Vinz had: “I suppose this renders both useless to plants? Will they dissolve back into solution eventually?”

[Addie]

Interesting.... I am having problem with my tank that become cloudy recently. I also just started to use KH2PO4 recently due to the higher operating cost of Seachem Phosphorus. I'll try to dose at separate day and try the seachem again since I still have a little left. I have been trying to figure out what went wrong til date .... thanks for sharing this