Nitrate and Phosphate consumption

[Domi]

Hi all,

 

I have a 8 gallon cube running since may with mostly SPS. And my Nitrate and Phosphate consumption is really high. I feed 3 times a day and dose 3ppm NO3 (with a mix of MgNO3 and CaNO3) and 0.03ppm PO4 (KHPO4)  per day, still the levels are 0 or only slightly above zero the next day. Since I started dosing NO3 and PO4 my SPS are growing pretty fast, but can they consume that much? I do not use a skimmer or any other filtration. Additionally, I dose ATI nano essentials, alkalinity consumption is around 1 dKH/ day.

The rock is all live rock, so I don't expect that it is the cause for the high consumption. Except for some algae on the glass every couple of days, I don't see any algae growth. Also the macros on the rock are not growing.

 

Here are my average values throughout last week and used tests:

Alk: 7.5 (Hanna)

Ca: 400 (Salifert)

Mg: 1200 (Salifert)

PO4: 0-0.01 (Hanna ULR)

NO3: 0.5 (Salifert)

 

Do you think that is just consumption from the corals? I attached a FTS so you can see how much coral I have.

How much do your tanks consume?

I am now dosing by hand and measuring daily, would you just set the dosing pump to dose 3ppm NO3 and 0.03ppm PO4 a day and only measure weekly? I am a little bit worried to do that since values would rise a lot if consumption suddenly stops.

Another way would be to further increase feeding, could this have negative effects? I guess it will lead to more detritus?

My livestock except corals:

1x Hermit crab

2x Turbo snails

1x Lysmata debelius

1x Lysmata amboiensis

1x Tail spot blenny

 

Thanks for your input,

Domi

 

[mitten_reef]

2 hours ago, Domi said:

I do not use a skimmer or any other filtration.

So you only use filter floss on the return side?  No purigen, no chemipure, no phosguard and the like, no carbon?  

 

PS your corals do look nice and healthy.

[Domi]

11 hours ago, micoastreefing said:

So you only use filter floss on the return side?  No purigen, no chemipure, no phosguard and the like, no carbon?  

 

PS your corals do look nice and healthy.

I don't even use filter floss, I only have the tunze nano stream on the back for water movement no return pump.
The corals were very bright before I started dosing and feeding a lot, now they start to color up, so I definitely think they don't like the low nutrient levels I would have without adding that much.

[mcarroll]

Don't overfeed.  Don't underfeed.

 

Test and dose for both N and P daily until you know the actual consumption rates for them.  

 

Target 0.03 ppm for each phosphate dose.  

 

Target 5 ppm for each nitrate dose.  

 

Once you see the consumption pattern you can start spacing out your tests.  (This should be about the same way you figure out alkalinity dosing, btw.)

 

Just as with alkalinity dosing, if there are any major changes to the tank you may have to begin testing again to recalibrate your N and P dosing.

 

Likewise, you should worry approximately as much about on-going N and P testing as you do about ongoing alk testing.