Thanks for your feedback!
I target feed reef Roids weekly and daily feed frozen baby brine shrimp for my mandarins so I feel like they’re getting the organics.
but for whatever reason if I try raising my nitrates with excess feeding, my nitrates stay at 0 and my po4 spikes.
yesterday I got Sodium Nitrate and will start dosing 3 times a week.
Do aminos raise po4 and nitrate? Also should I bump up target feeding to twice a week?
Ok here is a "reef nutrition 101" primer for ya. Might be long but should be helpful.
First of all, all organisms uptake N and P in a fixed ratio (google Redfield ratio and its related research). Here i dont just mean no3 and po4. N means all nitrogen nutrition sources like amino, proteins, ammonia, no2, and no3. Likewise, P includes po4 as well as dissolved organics, waste, and freeflowing p ions. In nature, the ocean averages out to about 16N to 1P, but different organism's N to P uptake have ratios that are slightly different. I dont remember the exact numbers. But generally, corals and algae are 20-22N to 1P. Phytoplanktons 16:1, bacteria/pods/fish: 5-10N to 1P.
So when tanks struggle with high po4 and low/no no3, that simply means the NP ratio of what you feed doesn't match the NP ratio of what ur tank uptakes and exports. In your case,, either you are putting in too much P, or your tank isn't processing enough P. Let's look at each
Input
Reef roids - their main ingredient is plankton, so should be pretty close to the default NP ratio
Brine - meaty foods tend to have relatively more P since its shrimp. Generally higher up the food chain has more P. But in your case it should be fine bc meaty food offer a lot more benefits in other areas. When you feed, do you keep the melted "juice"? I've heard anecdotal reports that the juice contains high P depending on the maker of the brine ice cube tho have not been able to verify.
Proteins - mostly made up amino acid chains but can contain P
Amino - a simple peptide chains of C, O, H and N. Contains no P.
So on the input side I think what you are currently doing is fine, upping reefroid is ok but adding amino is better. Adding sodium nitrate can help too indirectly on the uptake side ( more on that later)
Uptake
This is where I think your issues are. Your tank currently uptake N a lot more than P. usually points to a lack of biodiversity/maturity/balance. How old is the tank? Low P uptake/high N uptake usually points to your established bacteria/pods population (or even fish) being low relative to your algae/coral population. If your tank is young, then really time is the only true long term solution for these various organisms to stabilize. If your tank is already mature and established, then really you just need to match the "in" ratio with the "out". Dosing more N will help. Recall that everything uptake N and P in fix ratio - this means when your N is low, the P absorption slows down too. This is where dosing specifically sodium nitrate can help po4 even if it doesn't directly benefit your corals. Since algae takes up no3/po4, directly increasing no3 will unlock ur algae growth that will then absorb the po4 too. Do you have a fuge? This will help make sure the algae growth is contained in the fuge, instead of a potential GHA explosion in your DT or excess zoox growth (remember zoox is algae too) that will cause coral browning.
Dosing amino in this case may help indirectly with PO4 by enabling corals take more P from protein and disolved organics before they become po4, tho the exact processes there im not too certain
Export
Skimmer - Pulls out mostly waste and dissolved organics, will contain n and p closer to average, slightly leaning more P side
WC - depends on the concentration from test results. Doing it now when you have no no3 will mean its all P being exported. The detritus being vacuumed out will also slightly more P than N.
Manual removal of algae - will be specifc to the ratio of the algae used. Ie chaeto/gha. 22:1
GFO - only pulls Po4 - super effective but also can mask other problem and delay/prevent tank from reaching natural maturation and balance. Not recommended unless you have a very good handle on the rest of the biological and nutrient cycle of your tank. It doesn't address the true culprit of your tank's N to P imbalance and will come back as soon as you stop using GFO
Bottom line, its simply about matching your "in" with the "out". Once you understand how nutrients travel thru your system, you can make more educated decisions on how to adjust either your "in" or "out". Over time, the NP ratio of your tank will change as corals and fish grow, so its important to keep this in mind and adjust accordingly.
