Huge Phosphate Spike Overnight. Why?

[Bells>Waimea]

I've been trying to get po4 in line lately. Found out my source water has about .05 po4 so top off isnt helping, but unable to get clean water at the moment.

I tossed in a small amount of phosguard the other day and it dropped from .22 to .18 and then .16 yesterday.

I fed the tank once yesterday pretty heavy. Frozen misis and reef roids. I know this would raise nutrients, but I was ok with it as I didn't want to drop it too fast anyway.

Just tested with the Hanna ULR Phosphate checker 3 times in row and I got .4, .38, and .36. Could I really get a jump that high from one large feeding? I wouldnt think that would be possible. Is there something up with my hanna checker? Not sure why I would get such a huge jump over night, not to mention the different readings back to back.

Anyone have any ideas on what could be the cause of such a big spike?

thanks

 

[lavoisier]

Can you write a few words about your tank? Water volume, bio load, feeding schedule and ingredients...

Any chance some livestock expired?

 

[SliceGolfer]

Reef roids will cause a spike. I’ve experienced this myself and there are plenty of supporting threads.

 

[Bells>Waimea]

Can you write a few words about your tank? Water volume, bio load, feeding schedule and ingredients...

Any chance some livestock expired?

20 gal tank 15 gal water volume. Feed every other day. Nothing has died lately. Reef roids once a week and mysis. Every other day. Very Small amount usually.

The other day is was a heavy amount of both as I didn’t want to drop phos too fast with the gfo. But had no idea it could spike like that with one heavy feeding.

 

[Bells>Waimea]

Reef roids will cause a spike. I’ve experienced this myself and there are plenty of supporting threads.

I’ve heard stories as well and expected it to raise po4 but not like that.

 

[Duffer]

Definitely reef roids, and that’s the reason I switched to benepets

 

[Randy Holmes-Farley Verified Community Expert]

Foods are nearly always the main source of phosphate, and it doesn't matter if the food is eaten or not. One day's feeding can boost phosphate by 0.02 to 0.3 ppm or so.

I show that here:

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com