Nutrient Levels Going to Bottom Out

[hoffmeyerz]

I think I have an understanding but could use some back up here.
I run a 75gal tank that is about 3 1/2 years old. It ran pretty stable with nutrient levels staying with NO3 about 20 and PO4 about .09. levels were slightly high but tank ran well and I didn't have any coral so I left things alone. It wasn't heavily stocked and I ran Phoshgaurd along with my skimmer to keep things in check.
In March I added my first corals, some Daisy Zoa's, Forest fire Mushroom, and an Aussie Goni. After adding those I started getting a large algae outbreak that I attributed to the increased light period I was now running. I previously couldn't keep any clean up crew alive more than a few months because there wasn't enough in the tank for them to eat but now I had plenty so over time I've added an urchin, three turbo snails, an algae blenny, and a couple peppermint shrimp to eat the hydroids.
I've watched levels keep slowly dropping until today I tested NO3 at 8.3 and PO4 hit 0.
I'm a little concerned about bringing on a Dino attack. I've increased my feeding but that hasn't made a change. I'm assuming that the clean up crew is REALLY doing it's job along with the corals stripping out of the water column.
I'll increase feeding more and should I maybe add a fish or two to add to the bio waste load? Right now it's 2 clowns and 3 pajama cardinals besides the cleanup crew. When should, if I should, consider dosing nitrate and/or phos?

 

[Miami Reef]

Add more fish or increase the amount you currently feed.

You can also add reef roids or other high PO4 particulate foods.

There is a study that shows phosphate deficiencies can cause coral bleaching, so if you still can’t register a PO4 number with the feedings, you may need to dose pure food-grade sodium phosphate.


You may also opt to jump straight into dosing PO4 if you’d like. It’s quicker.

Study about phosphate deficiency promoting bleaching: https://pubmed.ncbi.nlm.nih.gov/28242282/

Pure sodium phosphate food grade on Amazon (more inexpensive and better quality grade than Brightwell Phosphate) https://a.co/d/8XhCWFo

Calculator to dose the phosphate product: http://www.theplantedtank.co.uk/calculator.htm

Select phosphate from potassium phosphate.


The recommended PO4 range is 0.02ppm-0.10ppm, with higher being better than lower.

If you have any other questions, feel free to ask.

 

[hoffmeyerz]

Thanks @Miami Reef
I was considering feeding reef roids. I had opted not to until now because all coral looked good (although the Goni has been more pulled in recently) and I was leaving well enough alone but now seems like it might be a good time to give some a go.
I was unaware of bleaching from low PO4, thanks for that info.

 

[Miami Reef]

Thanks @Miami Reef
I was considering feeding reef roids. I had opted not to until now because all coral looked good (although the Goni has been more pulled in recently) and I was leaving well enough alone but now seems like it might be a good time to give some a go.
I was unaware of bleaching from low PO4, thanks for that info.

Gonis in general a very finicky coral. I have some that do well and others that don’t and eventually die. Very strange.

Don’t base your success on them. If everything else looks good, I would still raise the PO4, and I wouldn’t beat myself up if the goni still doesn’t puff back out.

 

[hoffmeyerz]

Gonis in general a very finicky coral. I have some that do well and others that don’t and eventually die. Very strange.

Don’t base your success on them. If everything else looks good, I would still raise the PO4, and I wouldn’t beat myself up if the goni still doesn’t puff back out.

I appreciate that, if it's one thing I've learned over the last four years is don't knee jerk and be patient!
The Goni puffed way up and looked great after first placing it in the tank. I've just been monitoring it since it's pulled back in but not really making big changes. It has since started to come out more but only about half of what it was doing. The other corals are looking real good, maybe a reef roids feeding will do it some good!

 

[MrGisonni]

My goniopora hate when Nitrates are below 15 FWIW. They don't seem to mind at all if phosphates are at .02 or .10 though. As mentioned above, reef roids are a good way to keep Phosphates in the appropriate zone.