Nitrates Phosphate and Marine Pure Blocks

[SifuMemphis]

Since my DT tank doesn't have a lot of rock, I went with a lot more Marine Pure Blocks in my 150g tank. Can having too many MPB in the sump lower nitrate and phosphate too low? My nitrate is stable at 5ppm (even with heavy feeding / dosing nitrate and P04) and Phosphate readings are ALWAYS 0. Tested with Salifert and Hanna. Nothing I've been doing can get p04 up.

Things I've tried:

Feeding more frozen food
reef roids
oysterfeast
flakes, pellets

I wonder if having too many MPB is causing it to read 0 p04? Any help would be great. Thanks

 

[Adamantium]

Following along with the same question. My tank has pretty low nutrients, but I have a perfect spot for a Brightwell Xport brick. Not sure if it would bottom things out.

 

[andrewey]

As far as I know, no one has been able to demonstrate that Marine Pure blocks reduce nitrate levels in the reef aquarium. There are anecdotes from many hobbyists claiming they either had an effect or had absolutely no effect on nitrate levels. I believe there were some tests on RC where they did not find a reduction and some testing done by BRS that was inconclusive due to experimental design. As such, you are likely to recieve anecdotal evidence for/or against their use or simply conjecture. I'm not sure anyone could answer definitively one way or another.

If I were in your shoes, I would first investigate the accuracy of my testing kits, investigate any other forms of nutrient reduction (cheato, skimmer, ats, carbon dosing, WC, etc.) and finally, dose a set amount of phosphate and retest to determine test kit accuracy/resolution and phosphate reduction rate.

 

[Randy Holmes-Farley]

I don't think marine pure does much for phosphate either.

 

[SifuMemphis]

I don't think marine pure does much for phosphate either.

Yeah, I am trying to figure out my nutrient issue right now. The tank is about 5-6 months old, and has about 4 baby tangs, 1 wrasse, and 2 clowns, and my nitrates WILL NOT budge above 5ppm, and when using Hanna AND salifery p04 tester, shows zero. The hanna is the phosphate, not the ULR one.

I've been feeding a lot, as well as dosing 25ML of Neonitrate / NeoPhos in every other day, yet still reading zero. Tank is 150g

I have my skimmer turned off, and my fuge light turned off. Last night, I just removed the chaeto all together so the fuge is empty. I am at a loss on why it's still reading low.

Currently the tank has a minor case of Dino, which is why im trying to get the nutrients up. Any idea why? Or is Nitrate and p04 something slowly going to come up.

 

[SifuMemphis]

If I were in your shoes, I would first investigate the accuracy of my testing kits, investigate any other forms of nutrient reduction (cheato, skimmer, ats, carbon dosing, WC, etc.) and finally, dose a set amount of phosphate and retest to determine test kit accuracy/resolution and phosphate reduction rate.

Yeah, I tested with 2 different p04 testers (hanna and salifery) as well as Salifert Nitrate and Red sea nitrate, and both reading 5ppm ish. Some odd reason, nutrients are just low in this tank and won't go up, even with every other day dosing (everyday heavy feeding)

 

[Crustaceon]

IME, I’ve had to dose phosphate every day for a week straight to get it above zero. I honestly think the zero reading has a lot to do with Po4 binding in the rock/sand/bio media until a sufficient point of saturation is reached. Once I held .08ppm Po4 for two days in a row without dosing, it never dropped lower again.

 

[SifuMemphis]

IME, I’ve had to dose phosphate every day for a week straight to get it above zero. I honestly think the zero reading has a lot to do with Po4 binding in the rock/sand/bio media until a sufficient point of saturation is reached. Once I held .08ppm Po4 for two days in a row without dosing, it never dropped lower again.

So potentially, you're recommending keep dosing until it hits that "saturation point" ?

 

[Crustaceon]

So potentially, you're recommending keep dosing until it hits that "saturation point" ?

That’s what I had to do. I would bump Po4 from zero to .08ppm. The next day it would be right back at zero. In my case, I repeated this process for a week until Po4 stabilized. I haven’t had to dose phosphates again.

 

[SifuMemphis]

That’s what I had to do. I would bump Po4 from zero to .08ppm. The next day it would be right back at zero. In my case, I repeated this process for a week until Po4 stabilized. I haven’t had to dose phosphates again.

Thanks i'll just keep dosing each day until I get a reading

 

[Greg P]

I too have needed to dose both NO3 and PO4 for over 4 months now just to get myself to 0.03-0.06 and 2
I've also lowered my Alk from 8.3 to 7.5-7.7

I am still waiting for that 'threshhold' where they saturate the sand/rocks and then I'll need to back off the dosing.
In the meantime, my corals haven't looked better. Awesome colors

 

[Randy Holmes-Farley]

I too have needed to dose both NO3 and PO4 for over 4 months now just to get myself to 0.03-0.06 and 2
I've also lowered my Alk from 8.3 to 7.5-7.7

I am still waiting for that 'threshhold' where they saturate the sand/rocks and then I'll need to back off the dosing.
In the meantime, my corals haven't looked better. Awesome colors

FWIW, there is no true "saturation" point, except if you mean at a fixed phosphate concentration in the water. The mineral surface can hold a lot more at 1 ppm phosphate than at 0.1 ppm phosphate.

 

[Greg P]

FWIW, there is no true "saturation" point, except if you mean at a fixed phosphate concentration in the water. The mineral surface can hold a lot more at 1 ppm phosphate than at 0.1 ppm phosphate.

Although I understand enough to deal with my tank, my ability to get the point across isn't always enough to be correct