Hey guys, i’ve been having issues with my tank for years (see older threads if interested) my coral slowly withers away over the course of about 6 months. After getting better testing equipment (salifert nitrate, hannah phosphate) my phosphate is showing up at 0.00. Nitrates have been between 10-15ppm. I got an ICP test that confirmed my phosphate is undesirably low. How do I increase phosphate without increasing nitrate? I have a moderatly stocked 75 gallon tank and feed about a cube of frozen food plus nori every day. I read in a previous thread that dosing phytoplankton can help a lot since they are high in phosphates. Ideally I would like to figure out a new feeding routine rather than dosing phosphate on a regular basis. Btw, I don’t run GFO or carbon and my only filtration is an over powered protein skimmer (reef octopus 150) and crushed live rock in my sump. Any recommendations for increasing phosphate without increasing nitrate?
Phosphates 0.00, nitrates 10-20ppm
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ReefBeta
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I just start dosing phosphate.
Mine was similar, 20 ppm nitrate, 0.01 or lower phosphate, and I have dino problem. So I just start dosing phosphate to fix the imbalance, and increase my algae reactor photoperiod to export both more.
Mine was similar, 20 ppm nitrate, 0.01 or lower phosphate, and I have dino problem. So I just start dosing phosphate to fix the imbalance, and increase my algae reactor photoperiod to export both more.
Crashnt24
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Wow, I wish I had your issue. I have 0 nitrates and .08 phosphates.
I always hate dosing unless a last resort. You need anoxic zones for natural NO3 reduction. Also a refugium or a turf scrubber. Macros consume more NO3 than phos. Increase feedings of dirty foods(pellets, un-rinsed frozen) after NO3 reduction methods are put in place.
Reasons I hate dosing:
You are adding more than the desired nutrient. It's always attached to another compound that builds up in the water column. It's also expensive and time consuming. You gotta dose daily, then perform additional water changes to keep that additional compound in reasonable levels.
It's much more worth your time and energy to change your filtration to maintain levels you desire. Once you get it set up, it's like cruise control. Much cheaper and less maintenance.
I always hate dosing unless a last resort. You need anoxic zones for natural NO3 reduction. Also a refugium or a turf scrubber. Macros consume more NO3 than phos. Increase feedings of dirty foods(pellets, un-rinsed frozen) after NO3 reduction methods are put in place.
Reasons I hate dosing:
You are adding more than the desired nutrient. It's always attached to another compound that builds up in the water column. It's also expensive and time consuming. You gotta dose daily, then perform additional water changes to keep that additional compound in reasonable levels.
It's much more worth your time and energy to change your filtration to maintain levels you desire. Once you get it set up, it's like cruise control. Much cheaper and less maintenance.
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What level of P did the ICP show?
Feeding will boost both N and P, if you go that route.
I would go the feed more route.
Your fish and tank will be happier.
Your fish and tank will be happier.
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You might want to rethink that opinion, at least for phosphate dosing.
Let's explore that assertion, since it seems VERY highly suspect to me.
Let's suppose that to correct a phosphate deficiency, you choose to dose 0.03 ppm of phosphate every day.
Let's also suppose you choose to dose trisodium phosphate with a high purity (99.9% and also food grade, for example).
Dealing with the claim of the "another compound" issue. Trisodium phosphate is 58% phosphate and 42% sodium. So each day you are also adding a bit under 0.03 ppm of sodium.
Would anyone think that such an addition would benefit from a water change? Absolutely not.
35 ppt seawater contains about 10,800 ppm of sodium.
If you dosed 0.03 ppm of phosphate using this product every day with zero water changes, over a WHOLE YEAR sodium will only rise by 4.6 ppm. So sodium rises from 10,800 to 10,805 ppm. There is no reef aquarium anywhere that controls sodium anywhere close to that amount. Salt mixes diverge by hundreds of ppm in sodium present at 35 ppt, and evaporation and top off (even with an ATO) will swing sodium up and down by far, far more than this every day.
OK, so I, at least, conclude that the idea that phosphate dosing requires extra water changes is a myth that is busted.
Let's look at cost.
This product:
TriSodium Phosphate Anhydrous (TSP) - US Food Grade Granular
Shop Prescribed for Life for your supply of trisodium phosphate powder. You can use this natural product as a degreasing and cleaning agent safely or for internal.
pforlife.com
is of the quality I mention above, and costs $22 for 340 grams.
What can you do with that?
It is enough phosphate (197.2 grams or 197,200 mg) to add 0.03 ppm phosphate to 6,573,333 liters of tank water.
Since most tanks are not that big, let's look at what it does for a 100 gallon (378 L) tank. It can add 0.03 ppm phosphate to that 378 L tank 17,389 times, or every day for 48 years.
Thus, for $22 you can make a lifetime investment, or you can sell a years worth to 47 of your reefing friends and still have a years supply. Or you can buy less.
As before, I conclude that the idea that phosphate dosing is expensive is a myth that is busted.
Crashnt24
Well-Known Member
You might want to rethink that opinion, at least for phosphate dosing.
Let's explore that assertion, since it seems VERY highly suspect to me.
Let's suppose that to correct a phosphate deficiency, you choose to dose 0.03 ppm of phosphate every day.
Let's also suppose you choose to dose trisodium phosphate with a high purity (99.9% and also food grade, for example).
Dealing with the claim of the "another compound" issue. Trisodium phosphate is 58% phosphate and 42% sodium. So each day you are also adding a bit under 0.03 ppm of sodium.
Would anyone think that such an addition would benefit from a water change? Absolutely not.
35 ppt seawater contains about 10,800 ppm of sodium.
If you dosed 0.03 ppm of phosphate using this product every day with zero water changes, over a WHOLE YEAR sodium will only rise by 4.6 ppm. So sodium rises from 10,800 to 10,805 ppm. There is no reef aquarium anywhere that controls sodium anywhere close to that amount. Salt mixes diverge by hundreds of ppm in sodium present at 35 ppt, and evaporation and top off (even with an ATO) will swing sodium up and down by far, far more than this every day.
OK, so I, at least, conclude that the idea that phosphate dosing requires extra water changes is a myth that is busted.
Let's look at cost.
This product:
TriSodium Phosphate Anhydrous (TSP) - US Food Grade Granular
Shop Prescribed for Life for your supply of trisodium phosphate powder. You can use this natural product as a degreasing and cleaning agent safely or for internal.
is of the quality I mention above, and costs $22 for 340 grams.
What can you do with that?
It is enough phosphate (197.2 grams or 197,200 mg) to add 0.03 ppm phosphate to 6,573,333 liters of tank water.
Since most tanks are not that big, let's look at what it does for a 100 gallon (378 L) tank. It can add 0.03 ppm phosphate to that 378 L tank 17,389 times, or every day for 48 years.
Thus, for $22 you can make a lifetime investment, or you can sell a years worth to 47 of your reefing friends and still have a years supply. Or you can buy less.
As before, I conclude that the idea that phosphate dosing is expensive is a myth that is busted.
Meh, I will always prefer to avoid dosing unless it's a last resort.
Example being that I have dosed nitrate and phosphate after my system bottomed out. I dosed as a temporary solution until I could maintain the levels that I wanted naturally. I scaled back my refuge lights, added more fish and increased feedings. Now I don't have to mix sodium nitrate and sodium phosphate. I don't have to dose everyday and test my water everyday to adjust dosings. Also less water changes as sodium was creeping up on my ICP tests.
Currently my NO3 is just barely detectable and PO4 is slowly moving to my target of 0.05
Again, I'm all for it as a last resort. Just not a permanent solution unless you like
wasting time everyday.
Agreed on the sodium not being a deal breaker, just another slight negative IMO. My ICP tests definently showed elevated levels of sodium, although not dangerous, I would just prefer to not even deal with it if I don't have to.
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Lots of good advice, thanks. I’m going to start dosing, hopefully just for the short term. I have been trying to raise my nutrients by feeding more, but I only seem to be raising nitrate. I’m afraid that if I just continue to feed larger volumes I will continue to raise nitrate instead of phosphate. Does anyone have any advice for a phosphate heavy food? I’ve heard flakes/pellets and phytoplankton are phosphate heavy, I will try adding those to the menu. Hopefully this is a short term issue due to phosphate being fully depleted from the tank at one point, and nitrate was able to rebound quicker. I can’t think of any other reason i’d be having this issue, since I don’t run GFO.
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That's certainly a fine choice to not dose . But you keep posting misleading stuff about elevating sodium. That will force me to keep posting why that is wrong.
Many folks dose sodium bicarbonate or carbonate for alkalinity. Boosting alk by 1 dKH (0.36 meq/L) with sodium carbonate or bicarbonate adds 0.36 mmoles of sodium per liter, or 8.2 ppm of sodium PER DAY. That's 273 times as much as the phosphate dosing. That's the place to look if you use that sort of material and your elevated sodium did not come from your salt mix.
What about salt mixes?
Here's a study that Craig Bingman did a number of years ago.
How much does sodium vary? At a fixed 35 ppt salinity, sodium varied from a low of 10,166 ppm in Tropic Marin salt mix to a high of 11,592 ppm in Seachem salt.
If you start with normal 35 ppt ocean water at 10,800 ppm, how long would it take before you rose above the Seachem salt mix level of sodium? At 0.03 ppm per day? 72 years with no water changes and no correction for the salinity rise.
That is what you call a slight negative? All but one of salt mixes in that study started low in sodium. For them it is a slight positive. lol
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Radman73
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Dosing PO4 is a good way to go. It's what I did back when I had 0 PO4 but 5-10ppm NO3. I experienced the same results as you when I fed more, higher NO3, but no movement in PO4. Just a word of advice, calculate how much you need 3 times, and then cut it in half before dosing. You want small changes at first. Good luck!
blasterman
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What I use.
I've found that birdsnests corals in particular are sensitive about very low phosphate levels.
I have very similar NO3/PO4 to you. Still working on getting my PO4 up a bit and stable.
I’ve chosen to feed more rather than dose PO4. Can fatten up the critters more that way. Also, dosing PO4 seems to be part guesswork, since it can disappear (i.e., become invisible to your test kit) quickly even though it’s not necessarily getting taken up in biomass. Or maybe not the right biomass.
ReefRoids has a reputation for tending to raise PO4 more than other foods. I use it, sparingly, and have no reason to disagree. The name of the product isn’t to my liking (disrupts my coral reef buzz by evoking smelly gyms with death metal blaring), but my corals seem to be fine with it.
I’ve chosen to feed more rather than dose PO4. Can fatten up the critters more that way. Also, dosing PO4 seems to be part guesswork, since it can disappear (i.e., become invisible to your test kit) quickly even though it’s not necessarily getting taken up in biomass. Or maybe not the right biomass.
ReefRoids has a reputation for tending to raise PO4 more than other foods. I use it, sparingly, and have no reason to disagree. The name of the product isn’t to my liking (disrupts my coral reef buzz by evoking smelly gyms with death metal blaring), but my corals seem to be fine with it.
For about 10 days I was dosing an amount that should have increased my chemistry 0.02-0.04, but it was getting used up almost immediately. I got a little frustrated and upped my dose really high two days in a row, then the tank went up to 0.14. I’m pretty sure if I had anything but leather corals they wouldn’t have been happy. It’s been a few weeks since then and levels are holding more steady now. I think I fixed the deficiancy and i’m getting some phosphate from food to stick around without dosing now. Leather corals seem happier, but i’ve noticed a HUGE difference in coralline algae. Everything that had been fading colored right back up. I’m also getting more algae in general so I have to do a little extra cleaning, but it’s worth it for happy corals. Hopefully it won’t be quite as bad when tank stabilizes and coralline fills in more.
So my advice would do it slowly and patiently. Also make sure you have a hannah phosphate checker or something more accurate than the API tests.
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