Issues with phosphate spikes.

marcosnano · Nov 20, 2023

I have problems with phosphates for a while, usually they are between 0.1 and 0.25 which is way too high.
I started using Brightwell Phosphat-E to drastically decrease it and I notice the fish started to look strange for a day or two, breathing heavily, moth wide open etc.

po4 went down and I was hoping I will be fine for at least a week or two?

boy I was wrong.

5 days later I notice one of the coral colonies started bleaching, others not open. I tested my parameters, po4 is around 1ppm!

how is that even possible? what causes phosphate to spike so drastically?

Randy Holmes-Farley · Nov 20, 2023

I would not conclude a value bear 0.1 ppm is way too high.

I’d also caution that there’s a big reservoir of phosphate likely bound to rock and sand that will come off when you reduce the level in the water.

Finally, foods typically add more than 0.1 ppm per day.

How are you measuring phosphate?

marcosnano · Nov 20, 2023

Salifert Phosphate Test Kit.

It's very hard to distinguish levels using this kit, shades of blue are very similar, but for sure I'm at over 1ppm right now, it is very much blue.

Randy Holmes-Farley · Nov 20, 2023

marcosnano said:
Salifert Phosphate Test Kit.

It's very hard to distinguish levels using this kit, shades of blue are very similar, but for sure I'm at over 1ppm right now, it is very much blue.

And you think a few days ago it was less than 0.25? That doesn't sound likely.

marcosnano · Nov 20, 2023

5 days ago. Yes. I was threating it with brightwell product.

I'm treating it again.

Randy Holmes-Farley · Nov 20, 2023

OK, so the idea is that lanthanum brought it down, then it rose again? That's normal. it will take a lot of repeated doses before it stays down.

If it was 0.25 than you treated, maybe dropped, but then it rose to 1 ppm, that's not normal, or likely to be accurate.

Reefahholic · Nov 21, 2023

Put these two on a feeder and let it consistently feed the exact same amount daily. Bye Bye spikes.

jda · Nov 21, 2023

If you want to get serious about phosphate, a Hannah Ultra Low is a good idea. It is a good tool that has a pretty accurate number and is much better than a Salifert kit.

When you use the LC, the water level can drop a lot. Then the rock and sand release a lot and bring the water level back up to nearly where it was before. Lather, rinse, repeat... and you can end up with many up/down events that look like a EKG. The up/down can be a problem over time for corals. It is a better idea to use the LC in much smaller and more frequent increments so that the up/down spikes are gone or nearly very small.