Should I continue dosing Neophos?

No3 and Po4 were absolute zero. I dosed B Ionic Nitrate and raised to between 5 and 10ppm probably nearer to 5. Over 8 days.
Using Neophos, 16ml in 100g over 2 days target .04ppm still at zero. 4th day dosed another 8ml test on 5th day still zero. Should I continue with the Neophos?
Container says 1ml in 1 gal = .25ppm dosed 1ml in quarter gal 2 pints of fresh IO read 1ppm dosed up again in same 2 pints to 3ml neophos and stayd at 1ppm! Should have been 3ppm doesnt raise above 1ppm. Is this because in 2 pints it saturates out and wont read more tham 1ppm the color on test is much darker blue at 3ppm stayed pale blue..

95g dt, 25g sump, tried feeding more with no results. Testing with salifert. Mixed reef, very slow growth 2.5 years in, colors not good. Not using gfo, skimmer always pulling very smelly skimite, have to skim wet to get it out of system, empty every 2 days. 1in sandbed, at water change syphon sand and always smelly water in 5g bucket so dont understand why no nitrares. Feeding more = more brown syphon water and odour.!

Sg 1.024
Mag 1400
Cal 440
Alk 8.9
Ph 8.3
Nitrate 5 -10
Phos 0 No3 and Po4 have always been 0 prior to dosing.
All salifert.

Was hoping dosing No3 and Po4 would improve growth and color. Started with B ionic nitrate 10 days ago so only recently.
Ok, should have posted in 'reef chemistry forum'

However, update.
Still dosing Neophos 60ml to date = .15ppm in 100g.
PO4 still 0 on salifert colour chart.
Should I continue now 10ml day until I get a reading?
Can I dose more than 10ml day?

NO3 still above 5ppm
I have read that the rocks 'soak up' NO3' with differing opinions!
Maybe this is causing the 0?
Thank you.


Premium Member
Sponges, biofilms and anything else living in your system will use phosphorus. To avoid posphate deficiency which really messes up coral's photobiology it should be above .03. If you want to read more here's some links:
An Experimental Mesocosm for Longterm Studies of Reef Corals

Phosphate Deficiency:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching:

Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata

Phosphorus metabolism of reef organisms with algal symbionts

Sponge symbionts and the marine P cycle

Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
Thank you Timfish, I have read through most of the links, I feel I have a good understanding of the importance of the No3/Po4 including the ratios. The link regarding Skeptical reefkeeping is very interesting!
I have now dosed 120ml of the Neophos and still 0 on the test. Increased to 15ml day. Will continue until I get a reading however low and hopefully be able to maintain with a weekly dose after monitoring for 7 days.
Update, I increased the dose to 20ml day, I know the salifert test kit is accurate because I tested with a instant ocean sample of one gallon. However now dosed 310ml and still 0. No3 dropped slightly so dosed back up to between 5 and 10ppm.Running skimmer on slightly wet however have read that the skimmer doesnt remove enough nutients to make a difference.


Premium Member
Something really likes it. Have you seen any change to the anything in your system? New or more sponge and/or more coral and/or algae? What was the test results when you tested 1 gallon of IO for phosphate? Have you done a side by side test of your salifert with a different test kit?

(Just FYI, I don't use skimmers since they skew the microbial populations in reefs.)
Now have dusty brown on areas of sand that is gone by mng, reappears as lights ramp up, if I move the sand around a bit it dissapears into the water colum. Also hints of red algae/ bacteria not sure which, that blows off easily with rigid air tube, feeder tube. Not much at all, noticed about a week ago.
Dosed the 1gallon IO with 1ml neophos as stated on label, it tested at .25 as suggested on the bottle.which indicates that the salifert test is more or less accurate.
The few zoas I have in the dt do seem to be a bit happier, slightly deeper colour and a bit more open than usual. Everything else is as before.


Premium Member
For starters be patient, it can take weeks to months for corals to recover from stress events. Excelllent way to verify your test kit is working well (I test my tapwater as it's consistantly about .2 mg/l) To avoid making to big a change to fast I'd just keep dosing as you are or you can "slightly" raise the amount you're dosing but be sure to test after 24 hours to be sure you're not dosing too much. In these scenarios where the animals and microbial stuff is sucking up something really fast a threshold can be met very quickly when dosing and it can very quickly become too much. Rather than brush or stir up the nuisance algeas I would gently siphon them off, for the sand the surface layer that's siphoned off withthe algae can be soaked in H2O2 for a few hours, rinsed well then let dry for a day or 2 and added back to the tank.
Update, 4 weeks and 490ml of neophos - the water turned blue!
Finally have a result around .01 to .03 on the salifert test. Dosed 20ml today, will test tmrw then wait a week and retest to find out how much the tank is using.
Sent for triton icp-oes test vials. Will check all parameters to confirm my figures, also will rent par meter from lfs to check output.
Thank you Timfish.