Feel very confused at my tank's parameters

[Mark Waltermire]

So I have a Lagoon 25 that's been set up for over a year now and has been moved 2 times in that past year due to moving out of a college dorm, going back home, and then moving into a college apartment, but not it's got a place to stay for the next 2 years without moving. The tank has and is doing great. All of the corals are thriving, growing, and making new heads. Some corals include Torches, frogspawn, Duncan, hammers, octospawn, maze coral, Trachyphyllia, Palys, RBTA, a piece of SPS that we don't know what it's called is even encrusting. I just added a Favia and two pieces of Acropora this past week and the ORA Red Planet looks as happy as it could be. For lighting there's a Radion XR15 run on 93% which is giving me excellent Par without overpowering and a MP10 is providing supplemental flow to the Jeboa return pump.

Now for the chemistry part,
I'm dosing 4.5ml of BRS soda ash daily and that keeps the alk at ~7.8dKH and then calcium is right near 440-425
Phosphate is 2.42ppm, yes that is correct. Not .242 or anything else.
Nitrate is at 15-20ppm.

I feed the tank one to two cubes of Mysis or Mysis and brine daily, and there's a maroon clown and a leopard wrasse in the tank, which between them and all the coral all of the food is consumed within about 2 minutes. I am not running filter socks or any sort of export method other than doing 40% weekly water changes.

I did not realize that the phosphate and nitrate were so high until yesterday as I don't usually test those parameters as I've never really felt a need to. My thing is that I could add a protein skimmer to the tank and I know that it would help to remove the nitrate and phosphate, but should I really even care? Everything in the tank is thriving and growing so should I just chalk up those parameters to nothing, or actually do something about it?

 

[piranhaman00]

What did you use to test the PO4?

 

[Mark Waltermire]

I just realized my poor grammar in the thread's title, so apologies on that

I used the Hanna LR phosphate checker, which reads 0-2.5ppm phosphate
Nitrate was tested using salifert's nitrate test kit

 

[Eagle_Steve]

Another thing to look at is the water for water changes. Is it RODI and you mix? Or are you buying pre mixed? You might want to test the water change water, just to see if it is a phosphate source.

 

[LegendaryCG]

Why fix what’s not broken? Might just want to Be cautious and feed a little bit less.

 

[Quietman]

"My tank looked great..then I started chasing numbers and it never looked so good again." That's a pretty common refrain.

Your nitrates aren't terrible and many run them there.

If you're happy how it looks and still want to bring down nutrients...just adjust things ever so slowly. Barely move the needle (.1-.5 ppm PO4 over a week or two) so everything can adjust. You won't hurt anything dropping to 0 right away - it's more about making sure your tank stays in balance and adjusts to new parameters.

 

[Magellan]

You are feeding a lot for just a couple fish, the extra food decomposing is where those levels are coming from. Try cutting up a cube into thirds or even fourths. I feed half a cube for 2 clowns, a damsel, and a 6 line, and there’s still plenty left over for my large CUC to feast on..never mind how much gets filtered out after I turn my pumps back on!

 

[Mark Waltermire]

Another thing to look at is the water for water changes. Is it RODI and you mix? Or are you buying pre mixed? You might want to test the water change water, just to see if it is a phosphate source.

I'm using a BRS 7 stage RODI with all good filters and Tropic Marin Pro salt

 

[Mark Waltermire]

If you're happy how it looks and still want to bring down nutrients...just adjust things ever so slowly. Barely move the needle (.1-.5 ppm PO4 over a week or two) so everything can adjust. You won't hurt anything dropping to 0 right away - it's more about making sure your tank stays in balance and adjusts to new parameters.

My question is what needle is there for me to move? I'm already doing large water changes as nutrient export

 

[Quietman]

You have options...slowly reduce food amount might be all you need. You could run some PO4 media (ever so slowly with that). I don't know if you have skimmer, if so you could start carbon dosing, or add bio-pellets. I'm not saying to do any or all as that's your call. If you decide to, I would recommend you pick one thing...change it slowly...test 2x/week...wait for stable readings for a couple tests in a row...repeat until you get where you want to be.

But first decide if, what and where you want nutrients to be and why. If it's just to get to some "where everyone thinks I should be" point, I'd think a long time on that reason. If it's because you're starting to notice algae and want to get PO4 down, ok..that's sounds like a good reason. You're sick of 40% weekly water changes (by the way...great job with that, more than I would put up with and I like doing WC) and want to get to 10% weekly...that's fine too.

 

[Eagle_Steve]

My question is what needle is there for me to move? I'm already doing large water changes as nutrient export

If you want to bring PO4 down and your only source is feeding (so it seems, as you are feeding a lot) is to gradually reduce feeding. This will limit the input and the water changes you do now will slowly reduce the level.

 

[Quietman]

As you can tell our advice is cautious, hesitant and to "go slow"...if you had a coral problem or losing livestock, there'd be all kinds of do this, do that advice. You have a good looking tank and healthy livestock. You're successful! We just don't want you to screw that up. Good luck!

 

[Mark Waltermire]

You have options...slowly reduce food amount might be all you need. You could run some PO4 media (ever so slowly with that). I don't know if you have skimmer, if so you could start carbon dosing, or add bio-pellets. I'm not saying to do any or all as that's your call. If you decide to, I would recommend you pick one thing...change it slowly...test 2x/week...wait for stable readings for a couple tests in a row...repeat until you get where you want to be.

But first decide if, what and where you want nutrients to be and why. If it's just to get to some "where everyone thinks I should be" point, I'd think a long time on that reason. If it's because you're starting to notice algae and want to get PO4 down, ok..that's sounds like a good reason. You're sick of 40% weekly water changes (by the way...great job with that, more than I would put up with and I like doing WC) and want to get to 10% weekly...that's fine too.

i think you’re right on just tread with caution on it and kind of just leave it alone. The 40% water changes is pretty much just a little more than a 5 gallon bucket so that’s why it’s so high. My mixing pump would put too much heat in the water if I just did a couple gallons at a time.