Phosphate Help

[JohnV8r]

I'm having a phosphate issue in my mixed SPS/LPS reef that seems to be from the sand bed in my display tank being stirred. Phosphates have been at a disappointing .12 the last several weeks since a spike to .5 that was caused by a powerhead blowing 1/4 of the sand bed all over the place.

Yesterday, I had a fighting conch and a monti cap both pinned behind a rock at the very worst location behind my rock stack. My only option was to dig some sand bed to get them out. I also have a Diamond Goby and a large female Maroon Clown that stir up the sand hourly. I'm not entirely surprised by the phosphate spike after the powerhead incident, but I am surprised that it is still at .4 after 24 hours. My nitrates are currently < 1.0 on an Elos test.

I currently run 1.5 cups of BRS high capacity GFO in a Phosban reactor for 196 gallons net volume.

I dose 2.2ml of vodka through dosing pumps throughout the day.

My question is this: I still was not below the desired < .03 phosphate before this latest spike. Should I:

a) increase the amount of GFO I am running,

b) increase the vodka dosing,

c) add vineagar to the vodka to increase the overall carbon dosing, or

d) all of the above

I really want to suppress the phosphates more aggressively.

Thanks in advance.

 

[bertoni]

GFO will be the fastest way to go. One issue is that the GFO might be exhausted rapidly with that much phosphate in the water column. If the output of the GFO reactor is not measurably lower than the tank, the media needs to be replaced. I'd check that.

Ramping up the carbon dosing might be useful, too. You could try either more vodka or adding some vinegar. If the tank is free of cyanobacteria and other microbial pests, I'd likely just stick with vodka for the moment.

 

[JohnV8r]

I'm going to check the GFO reactor output water. That's a great idea!

 

[JohnV8r]

OK, I just ran the output through my Hanna checker and came back with a .13 phosphate level in the output water. Interesting that .12/.13 is where the phosphate level has remained for the last 2-3 weeks.

Is it possible that the BRS high capacity GFO has a limitation such that even when the entire system volume has phosphate at .12/.13 it can't reduce it further? What would limit GFO like that?

I think I'll increase the vodka dosing by 20% and see what happens. Since I have been dosing with a doser in smaller doses throughout the day, I have not had cyano issues like I did when I would dose one large dose once per day.

 

[bertoni]

Any GFO (for our tanks) can reduce the phosphate level a lot lower than that. If the tank is still a lot higher than 0.14 ppm, I'd give it a bit longer, and see what happens.

Bumping up the vodka dose seems reasonable to me.

Good luck!

 

[JohnV8r]

I've bumped the vodka dosing from 2.2 ml daily to 3.3 ml daily. That is dosed every six hours in a 3 part RO/DI water to 1 part vodka mixture. Therefore, .825 ml of vodka is dosed every six hours.

I'll give that a couple of days see what happens

 

[JohnV8r]

OK, it's been a couple of days and the phosphates are down to .11 - .13 based on two tests with my Hanna Checker. The vodka dosing has been increased to a total of 3.3 ml per day dosed in four equal dosings of .825 ml.

I'm going to give this through Sunday afternoon and see where the phosphates are then. However, .12 - .13 was exactly where I was before the spike caused by my digging around in my sand to free the fighting conch and monti cap that wound up wedged behind my rock stack. I don't think I'm overfeeding; one cube of mysis shrimp, one cube of spirulina enriched brine shrimp, and a pinch of Omega One Kelp Flakes in the morning at 6:30 am. The same + a cube of Emerald Entree at 7 pm. 1-2 times a week I feed either a cube of Cyclops or a tablespoon of OysterFeast and PhytoFeast.

What is the next step if my phosphates don't come down? More vodka? More GFO? Add vinegar? Should I thoroughly clean as much of my sand as possible? Remove, clean, and replace my deep sand bed in my refugium?

I'll give you that my Hanna Checker is more accurate than the tests I was using previously. However, I have not had measureable phosphates until I had the powerhead blow 1/4 of my sand around. Now I can't get them back down to immeasureable levels (or at least < .03).

 

[JohnV8r]

Just to be sure, I checked the phosphates in my return water from my refugium. They are .12 as well.

 

[bertoni]

That sounds like a lot of food to me, but I'm not sure about the size of the cubes. I might change the GFO media and stop feeding for a few days, to see what happens.

Does the meter measure 0 phosphates in fresh RO/DI? Which model is this?

 

[JohnV8r]

The food is San Francisco Bay Brand, so the cube sizes differ from mysis to brine shrimp, etc. The food is gone within 60 - 90 seconds max. There are 11 fish for a 175 gallon display tank. I won't rule anything out at this point, but I think my post reads like more food than it actually is. Additionally, I had immeasureable phosphates with the same feeding routine before the sand bed got blown all over.

I can cut the food in half or hold off completely and see what happens, but I honestly don't think food is the source of the problem. It may help it go away, but I don't think it's the source. My only concern with cutting the food completely is the potential stress on the fish, particularly the tangs and anthias.

The Hanna Checker is the HI 713/Phosphate Low Range model.

TDS in my RO/DI water is 0. Phosphates are 0.00

I have to admit, I am baffled. I have had the rock for 4 years. My intuition tells me this has to be coming from the sand bed in the display tank because all of this started when a powerhead became dislodged and blew 1/4 of the sand bed all over the tank. I mean it was everywhere. I had a hair algae bloom almost immediately after and I've been fighting that slowly but successfully (manual removal, hermit crabs, urchin, etc) since the problem began. The hair algae is getting smaller by the week. I just haven't had a vexing issue like this for a long time. All the rest of my parameters are right down the middle of the fairway.

I get a little bit of sand bed movement due to water flow (never will use sugar fine sand again), and some additional turn over from my diamond goby constantly digging under rocks and my maroon clown taking a spot next to my RBTA down to the glass bottom.

I've got chaeto in the refugium, 3.3 ml of vodka dosed daily, 1.5 cups of high capacity GFO from BRS running in a phosban reactor (BRS's recommended amount per their calculator). I'm just going out of my mind with this.

Do I use the siphon gravel cleaner I have and go through the sand tomorrow or should I leave it alone since I think the sand turnover may be the source? I have a lot of rock in my display tank and only about 20-30% of my bottom is actually exposed sand.

 

[bertoni]

Unfortunately, the time it takes for the food to be eaten isn't important, because what goes in mostly comes back out. Digestion is not very efficient.

I'd probably leave the sand alone at this point, but I'm just guessing.

 

[Big E]

I wouldn't chase the number down like your trying to do short term. The bacteria levels need to balance out & you keep changing things with vodka dosing & GFO changes.

You kicked up a lot of small granules of detritus all over your tank & gave the algae a chance to get it which caused the bloom.

I wouldn't change anything except start blowing your rocks off & try to trap whatever detritus you can in a filter sock or something similar. It may have caused a bulld up of some detritus in your sump too..........if so siphon, it out.

I get a little bit of sand bed movement due to water flow (never will use sugar fine sand again), and some additional turn over from my diamond goby constantly digging under rocks and my maroon clown taking a spot next to my RBTA down to the glass bottom.

You also have a dusting of phosphate laden detritus on the surface of your sandbed now. You can let these guys work through it or...
Maybe just lightly siphon the bed at the surface so you don't get cyano, ect. If you don't want to siphon you could just use a stick just at the surface to get that detritus stirred up into your flow so it can be exported.

I will take 2-3 weeks but I'm willing to bet that number will work it's way back down.

 

[swcc]

The other day I was in my backyard wearing sneakers. My roof was replaced a few weeks ago and low and behold I stepped on a roofing nail left over and missed by the clean up. It protruded through my shoe's sole and was digging into my foot when I walked. Not the most comfortable experience and I had a couple options...one would be remove the nail or I could run to the store get some thick shoe inserts that would stop the nail from being able to penetrate into my foot... I chose to remove the nail. Anyways, remove the source is the sensible alternative there, and the same goes for your aquarium. Remove the source of the problem and replace. If the source is taken care of, you are then left with not having to take measures to fix the problems the source is causing. Yes it is a little bit of a days task to remove substrate from a larger tank, but, doing so is the best way towards longevity and of course from the experience you can adjust your husbandry to better maintain the new substrate and drastically lessen or eliminate the situation your experiencing now.

 

[dviper150]

The other day I was in my backyard wearing sneakers. My roof was replaced a few weeks ago and low and behold I stepped on a roofing nail left over and missed by the clean up. It protruded through my shoe's sole and was digging into my foot when I walked. Not the most comfortable experience and I had a couple options...one would be remove the nail or I could run to the store get some thick shoe inserts that would stop the nail from being able to penetrate into my foot... I chose to remove the nail. Anyways, remove the source is the sensible alternative there, and the same goes for your aquarium. Remove the source of the problem and replace. If the source is taken care of, you are then left with not having to take measures to fix the problems the source is causing. Yes it is a little bit of a days task to remove substrate from a larger tank, but, doing so is the best way towards longevity and of course from the experience you can adjust your husbandry to better maintain the new substrate and drastically lessen or eliminate the situation your experiencing now.

You should see a Dr about that foot. Could get tettani from that nail you stepped on.

 

[swcc]

You should see a Dr about that foot. Could get tettani from that nail you stepped on.

LOL... Nah it never punctured the skin, just poked the outer layer.

 

[JohnV8r]

You kicked up a lot of small granules of detritus all over your tank & gave the algae a chance to get it which caused the bloom.

I do blow the sand/detritus off the rocks regularly. However, the problem with sugar fine sand is it ends up suspended in the water column when my diamond goby and maroon clown kick it up due to its size and the flow in my tank. That leads to some of the sand and detritus settling on the rocks...and yes, that one area that gets the most settled sand/detritus is where the hair algae is the toughest to eradicate.

It may have caused a bulld up of some detritus in your sump too..........

You're correct about that. I removed all of my equipment from my sump during a semi annual sump cleaning and got every spec of everything out of the sump, skimmer, etc. shortly after the powerhead incident. The sump is still clean at this point.

I wouldn't chase the number down like your trying to do short term. The bacteria levels need to balance out & you keep changing things with vodka dosing & GFO changes.

That is an excellent point as well. The funny thing about this hobby is that when you reach a certain level of expertise you begin to think you have achieved control. You're right. I need to make adjustments and evaluate rather than shotgunning a bunch of different solutions. I think the fact that my nitrates can be eradicated in a matter of a couple of days makes me less patient about phosphates. Great point.

If the source is taken care of, you are then left with not having to take measures to fix the problems the source is causing.

This is another point that has resonates with me. Removing the sugar fine sand (to the extend possible) and replacing it with medium sized coral sand is on my list of projects. However, that is going to upset the balance in my tank because I will end up stirring up detritus and removing some of the nitrifying bacteria. There will inevitably be a period of adjustment that will take place from the new coral sand being put in the tank. Therefore, I would like to have my parameters back to a stable point so I don't hand grenade the chemistry while it's already less stable than usual. You're right though; I need to remove the source of the problem.

Unfortunately, the time it takes for the food to be eaten isn't important, because what goes in mostly comes back out. Digestion is not very efficient.

As always Jonathan, a well-made point. I'm going to cut the food in half for the next couple of weeks and see if that doesn't help me get out in front of the phosphates. If nothing else, it will accelerate the eradication of the leftover hair algae.

Thanks for your input everyone. I appreciate it.

 

[swcc]

This is another point that has resonates with me. Removing the sugar fine sand (to the extend possible) and replacing it with medium sized coral sand is on my list of projects. However, that is going to upset the balance in my tank because I will end up stirring up detritus and removing some of the nitrifying bacteria. .

Your forgetting that the bacterial element in your sand is most likely only existing on the nutrients accumulated in your sand in the first place... removing it is the way to go..you can remove it over time vs immediately if your concerned.

 

[bertoni]

I wouldn't worry about the sand just yet. It's possible that the feeding is the primary problem, even given the history. I ran with sugar-sized sand for over 10 years with no problems, even with a burrowing goby pair.

 

[JohnV8r]

Here's an update:

I cut the food in half for the last 5 days and was still getting a .11-.13 phosphate reading. I don't think food is my issue.

Yesterday I thoroughly stirred the sand to release any detritus, sucked out about 1/3 of the visible sand (I'm guessing 12-20 lbs was removed from my tank), and did a 30 gallon water change (15%).

This morning the phosphate reading on my Hanna checker was .11 from a water sample taken from the display tank. I checked the output water from my GFO reactor and it was .11 as well. I pulled the 1.5 cups of BRS High Capacity GFO out and put in 3.0 cups of the generic non-high capacity GFO I was using before I switched to BRS High Capacity. 3 cups is the amount the BRS calculator recommended for a non-high capacity GFO (1.5 cups was the recommended amount for high capacity). The GFO reactor output is now 0.02 from the sample from my GFO reactor output.

I don't want to jump to conclusions about BRS's High Capacity GFO. However, here is what my experience has been:

When I switched to BRS High Capacity GFO, my phosphates were .13.

BRS High Capacity GFO was never able to take my phosphates below .11 (Hanna Checker +/- 0.04 accuracy).

During a phosphate spike caused by my digging in the sand to get a fighting conch and a monti cap from behind my rock stack, my phosphates spiked to .5. BRS High Capacity GFO returned the phosphates in my system from .5 to .12. However, the GFO reactor output with the BRS High Capacity GFO was never better than .12.

When I went back to my old non-high capacity generic GFO, my GFO reactor output water had 0.02 phosphates.

Those are just the facts. I am going to reach out to BRS to see if they have any comments, recommendations, and/or if they do any regular quality control on their GFO batches. BRS High Capacity GFO is expensive compared to non-high capacity GFO and at this point I'm uncertain that it performs as advertised.

I would certainly invite any representative from BRS to respond to this thread.

 

[tankmates]

I have EXACT same problem, same GFO, almost same food source and same diamond goby .....few days back I got excellent advise from betroni...cut my food ...but started changing GFO every 2 days..within last 5 days...my phosphates are .06 from .18......I think you should also change GFO every couple of days till you get it to level where it is under control and then leave it for longer period....Just what is working for me..I did GFO change couple days back...then my phosphate was .12, now I am doing one more on saturday.