New 73 gallon tank setup

[DKoKoMan]

Wish I could give you some of my .025ppm phosphates lol

[Frogger]

I think I am figuring this out and am beginning to understand where I went wrong.

I have not added any nitrates to the tanks in about 4 days, I did a 20% water change this morning. This afternoon my nitrates are still 1.5ppm and my phosphates are 0. I have used multiple different test kits and different reagents from different packages with the same results. The calcium levels and the alkalinity levels are stable without adding any 2 part solution. This tells me that I have shut down the photosynthetic activity in my tank, including the coralline algae.

There is not a lot of information on the web about the relationship between phosphates and nitrates. Most of us including myself (past tanks) have never had to really think about the relationship because our goals were to lower them as much as we can because they were always high. Problem is I designed a tank that efficiently uses up the nitrates and phosphates so well I have one that is bottomed out at all times.

It appears that your nitrates can only go so high when your phosphate becomes the limiting factor. Because I should have seen a reduction in nitrates with the 20% water change.

I can't get myself to look at my corals. I feel that I have let them down. It is not the cost of replacing the corals that bothers me its that I am in charge of their care. I take great pride in my past ability at keeping corals and fish alive for long periods of time.

I will do another 20% water change tomorrow and will continue to do so until I get the balance of phosphates to nitrates in place

[Bblinks]

Having unbalanced po4 and no3 level is definitely not a good. It limits the growth since po4 in your case contributes to a vital part of it. Here is a one of the speaker from 2016 macna and I think he can explain this better than I can.https://youtu.be/ZRIKW-9d2xI

[Ryanerickson]

That's a very interesting video not to mention the speakers was pretty funny

[Bblinks]

Originally Posted by Ryanerickson

That's a very interesting video not to mention the speakers was pretty funny

Definitely one of the better speakers....some are so dry lol

[Frogger]

Originally Posted by Bblinks

Having unbalanced po4 and no3 level is definitely not a good. It limits the growth since po4 in your case contributes to a vital part of it. Here is a one of the speaker from 2016 macna and I think he can explain this better than I can.https://youtu.be/ZRIKW-9d2xI

Thanks for the video. It kind of opens your eyes to how little we know about what the corals truly need. Many of the top experts in the field have been running their reef tanks with much higher phosphates and nitrates then most of us hobbyist reefers do and had great success with those numbers. They have also had long term stability that few achieve.

I purchased some KH2PO4 yesterday and added it to my tank. I used a calculator that MYKA sent me to figure out how much I needed to add. I ended up adding 1ml of a solution of 1gram of KH2PO4 to 250mls of ro water. My phosphates are now at .02ppm.

I added .5ml of the solution today. I want to get my phosphates to .03 with my nitrates at 1.5ppm. Try to maintain that Redford ratio mentioned in the video. I will take this really slow and try to stabilize my tank to settle my corals down. I am happy I finally have measurable phosphates.

[Myka]

Keep in mind that the Redfield Ratio is the uptake ratio of phytoplankton. It is not the ratio in the ocean, nor is it the uptake ratio of corals. It is a good guideline to use though, just as long as you understand it. Really all the Redfield Ratio is doing is putting in perspective how tiny of an amount of PO4 you need in comparison to NO3.

FWIW, 1.5 ppm NO3 is 50x PO4 at 0.03 ppm. Redfield Ratio is 16x.

The way I see it is that no matter how hard we try to mimic nature, we just can't do it nearly as well, so we use fertilizers (literally haha) to try to supplement the corals. It works in many cases, but not all. It depends what's missing or lacking in your own system. There are examples all over the map of tanks with high nutrients and SWEET Acros, and there are examples of SWEET Acros in immeasurable amounts of nutrients. Everyone's tank is different, and this may not be your magic potion.

[Frogger]

Originally Posted by Myka

FWIW, 1.5 ppm NO3 is 50x PO4 at 0.03 ppm. Redfield Ratio is 16x.

The ratio is actually 33 to 1 because phosphate is 31% phosphorus by weight and nitrate is 21% nitrogen by weight.

I started with no nitrates and had unhealthy corals I dropped the phosphates to 0 and have very unhealthy corals.

For now I want to get the phosphates to .03ppm and stabilize it for a while. My nitrates for now seem to want to stay at 1.5ppm

I tested my phosphates this morning and they are back down to 0 so I added another 1ml of the solution and re test it tonight.