Confused on phosphate levels and what if anything to do
- Thread starter ID-Reefer
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OP
OP
ID-Reefer
Active Member
Just some notes.
My tank was stable for months. The N03 was 10-13 and P04 .04-.07. Then the sudden increase of phosphate without explanation. I understand stability is ideal thus the reason for posting this thread.
i primarily feed frozen (LRS + fresh clam mix I make). Supplement that with pellets soaked in vitamins. As I have for months. No change. If anything I’ve reduced the amount of pellets and haven’t used reef roids or the like since before the sudden increase.
I run a refugium and have since the beginning. Chaeto grows fast and harvest 50% every 3+/- weeks.
I had phosphates and nitrates start to creep up 6 months ago which was why I started dosing small amounts of nopox and it brought levels of both down. Till now. I understand chasing numbers isn’t always the right approach but I had great success and coral growth during that time of stability and want to get my P04 back close to what they were. The P04 is the only parameter that has changed significantly.
I’ve not done anything new or different that explains the increased amounts of P04. Beyond the reefmat or ceramic bio bricks.
My tank was stable for months. The N03 was 10-13 and P04 .04-.07. Then the sudden increase of phosphate without explanation. I understand stability is ideal thus the reason for posting this thread.
i primarily feed frozen (LRS + fresh clam mix I make). Supplement that with pellets soaked in vitamins. As I have for months. No change. If anything I’ve reduced the amount of pellets and haven’t used reef roids or the like since before the sudden increase.
I run a refugium and have since the beginning. Chaeto grows fast and harvest 50% every 3+/- weeks.
I had phosphates and nitrates start to creep up 6 months ago which was why I started dosing small amounts of nopox and it brought levels of both down. Till now. I understand chasing numbers isn’t always the right approach but I had great success and coral growth during that time of stability and want to get my P04 back close to what they were. The P04 is the only parameter that has changed significantly.
I’ve not done anything new or different that explains the increased amounts of P04. Beyond the reefmat or ceramic bio bricks.
Are you using a Hanna ULR for the phosphate tests? If so, the vials can get hazy and cause false high readings. I order new ones from BRS anytime I get unexplained high readings from mine.
OP
OP
ID-Reefer
Active Member
Yes. Hanna ULR. And I did think of that (although Im very careful using microfiber cloth to clean the vials during the procedure) but I recently bought a Hanna calcium checker and tried with an unused vile from that test. No difference.
So... you had lower levels... now they are higher... you trust the the test kit.. only a few things have changed... you even cut the dry food that might be a major contributor... your Cheato is growing well and being harvested as usual. It doesn't sound like you are adding any more phosphate than usual. That leaves only the alternative... Previously unseen phosphate is now showing up. I'm guessing here but... Is it possible that you have had some sort of release of bound phosphate in the display tank like maybe from dying Coralline, development of a low ph area (like maybe deep in the sand) where calcium carbonate is being broken down, or etc.?
OP
OP
ID-Reefer
Active Member
I trust the test kit in that it has always seemed to be accurate/consistent. My son who also has a reef tank has the same Hanna checker and Im going to run a test with his to make sure...
Yes on food, Chaeto... everything same as before. Coraline seems fine. Not sure about the sand bed. PH has been same as before. Sand bed isn't deep deep but I do have anywhere from 1/2" to 2" around the bottom. I never vacuum the sand, wrasses keep a lot of it turned up. There are a couple small semi dead areas. Ive stirred up the sand bed a few times moving some zoanthid rocks around, enough to cloud the water. Id expect maybe an increase in N03 or P04 right after that but its been 10-13 days since I stirred up anything.
So it must be coming out of the bio bricks I bought off amazon
OR my dry rock is releasing some back into the thank that it had soaked up?
OR my hanna is faulty.
OR ??? Not really sure... Corals all still seem healthy. Watching SPS close. All SPS, LPS etc. etc. look same as before.
I added more GFO and will test again soon. Unfortunately my skimmer overflowed in the middle of the night so that won't help. It only had about 6 ounces of skimmate when it over flowed so not a lot but enough to probably affect tests.
sixty_reefer
5000 Club Member
A couple of thing have happened that changed the availability of nutrients in your tank.
They where only small although large enough to lose the balance in the aquarium.
1. replacement of filter sock by reefmat
This will affect the availability of nutrients, the sock collects uneaten food and wile still in contact with the water column it will release the nutrients C N P in to your system, even if they are replaced daily it still means that there is a contact with the water column for a period of at list 24h.
The reefmat removes the uneaten food more or less straight away leaving the contact time in the water column to maybe a few minutes, meaning that the reefmat will be reducing important nutrients that were contributing towards the previous tank balance.
2. Media replacement in the sump
The bricks you are using now seem to have the ideal shape to contribute for nitrifying and denitrifying bacteria to populate and will be most likely in a dark area of the sump. The increase of this bacteria in a mature system can explain the increase in phosphates.
What’s happening is that now that you have less ammonia available due to the reefmat, nitrifying autotrophic bacteria increasing in the sump will be competing with nitrifying heterotrophs in the display for ammonia if most of the ammonia is being processed by the bacteria in the sump this will result in a small increase in phosphates.
This is due to the heterotrophs in the display utilise the nutrients C N P and the autotrophs in the sump only use the nutrient N and not touch the nutrients C and P in addition this will explain also why you are observing a decrease in nitrates.
hope it helps.
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OP
OP
ID-Reefer
Active Member
Seems plausible.
Your suggestions on where to go from here? I love the reefmat and putting the socks back in isn't an option. I can easily remove the bricks and see if it makes a difference - add small amounts back in over time. I can continue to increase GFO until the P04 starts to decrease. Combination of both... Thoughts?
sixty_reefer
5000 Club Member
personally I would just take my time and regain the balance again slowly and steady let the tank adjust to the new availability of nutrients in a natural way
A few things that you could consider meanwhile would be the following:
Is it possible to dial back the speed of the roller to keep nutrients in contact with the water column for longer? If it’s possible this will be beneficial to regain some nutrients.
Reducing the amount of Carbon dosing would be a option, your nitrates are going down and you may want to direct the issue before they get too low. reducing carbon dosing will be helpful here.
To keep the nitrifying in the sump you may have to start using phosphorus absorbing Media as a regular thing. Or reduce the media slowly until you find the sweet spot between display and sump microbe nutrient needs. The more you want for your microbes to aid with P the more media you will have to remove from the sump.
sixty_reefer
5000 Club Member
In addition I’d just like to add that most mature reefs rely mainly on heterotrophic bacteria for biological filtration. There is many articles and data supporting this.
for a tank that heterotrophic bacteria is the dominant species you can use this thread as a guideline to regain balance.
www.reef2reef.com
regarding your current phosphates don’t stress if it takes you a wile to bring them down, as many probably already mentioned there will be phosphates bound to the rock and substrate at this point and GFO may seem slow although it will lower eventually.
for a tank that heterotrophic bacteria is the dominant species you can use this thread as a guideline to regain balance.
The Third Nutrient
The third nutrient is my theoretical thinking on nutrients and understanding of aquarium stability and balance. The third nutrient or Carbon is a nutrient that not often talked about and little is known of its function and effects to the other Nutrients in reef aquaria, not much is know to...
www.reef2reef.com
regarding your current phosphates don’t stress if it takes you a wile to bring them down, as many probably already mentioned there will be phosphates bound to the rock and substrate at this point and GFO may seem slow although it will lower eventually.
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