First bivalve - for phosphate reduction

[MNscoe]

See tank details in signature block. Tank is one year old, seven small fish, two Nems, a few softies and trying LPS, plus CUC.

With no sump and no skimmer, my struggle is to balance sufficient feeding without driving nitrates and phosphate too high. Water parameters are fine, except phosphate has been hovering between 0.2–0.35. With more frequent canister cleaning, and I just added a small bag of GFO, I believe my phosphates will be somewhat lower.

Reading this forum, I really want to add one bivalve to help consume some phosphate. Is that reasonable? If so, which particular creature would you suggest a newbie start with? I was initially leaning towards an oyster, but am learning a clam may be a safer first choice?

 

[dloberry]

Clams can be difficult for any hobbiest, and clams require specific parameters. I personally would not recommend this route until you do some extensive research

 

[Mr. Mojo Rising]

I've read reports on this, its very interesting, but it would take a substantial number of clams to make any dent in nutrients, like basically need the tank full of clams and nothing else. One or even a handful of clams won't make any difference.

There is no substitute for proper filtration, I don't believe that trying to control nutrients through feeding is a good idea, the fish need to eat no matter what. Ideally you should have the proper filtration equipment to cover the bioload including the feeding. If you are struggling then perhaps you need to upgrade your filtration system to export more nutrients, a skimmer is a great filtration tool.

 

[resortez]

Oh man, this setup takes me back. Very nice, great learning experience. In my personal experience, water changes will be your biggest tool to keep PO4 at bay, there’s no slacking off with this type of setup. Your biggest allies will be all working fish & a massive CUC, urchins, serpent stars, hermits, snails, crabs, cucumbers, sea stars, shrimps, nassarius snails, hopefully you get pods to explode in the tank. Lots of flow to move detritus around & off rock & sand. Goby’s, bristle tooth tangs, a rabbit fish, blennies, a single wrasse to control bristle worms if you get some because you want to control the worm population, the bristle worms will help but can’t let them get out of control. Hope any of that helps, hope it makes sense. Good luck.

 

[Mebbid]

Maybe a hang on the back skimmer and some macro algae growing in the display?

Codium is pretty cool

 

[resortez]

That is an 80 gallon tank I had 15 years ago only on a eheim canister filter, nothing else. 15 gallon water changes bi weekly. I tackled 1/4 of the tank every time I did the water change, meaning a 1/4 section of the rock was removed & sand was completely vacuum syphon in that section. The canister was given a light clean by the 4th water change, then the routine was restarted. Tank did very well, to the point of the tomato clowns laying eggs & coral splitting. Miss that tank but it was work, there was no way around the work in order to lock it in.

 

[exnisstech]

Maybe @Subsea has an opinion? He likes filter feeders. I don't think it would reduce PO4 in a normal reef tank setting with just a clam or two but I don't really know. I've kept a few clams but never even thought about them having an effect on PO4

PS. Tank looks pretty new. I would think about just letting it run and see where it settles in. If it looks good don't fret the numbers and let it reach a state of normalcy without intervention.
I have a tank that runs PO4 0.4 - 0.9+ but the tank looks good so I relax and enjoy it.

 

[Tahoe61]

When I had predatory fish, and octopus I simply went to the supermarket and bought live little neck clams.
Some little neck clams thrived for months.

I am more inclined now to believe some bivalve are indeed useful in the uptake of nitrates and phosphates.

Go to the Sea Food section at most grocery stores and examine the shell fish. Look for tightly clamped shells with little smell. Little Neck Clams are pretty common.

 

[Subsea]

No to using a clam or an oyster to reduce only phosphate. If you are using GFO already, than switch to lanthanum chloride.

@MNscoe
While it’s true that clam biomass would have to include phosphate along with the nitrate, I have no idea what that ratio would be. In phytoplankton the N:P ratio is 16:1, in the macro algae Gracilaria Hayi the N:P ratio was 30:1 and in skimmate bacteria the N:P ratio is 5:1

Consider adding an HOB skimmer and carbon dose to export bacteria biomass.

If I read your post correctly, you just recently used GFO in your cannister filter for the first time. What else are you using for circulation in this 55G tank.

Not sure I understand your nutrient management. You want bivalves to reduce phosphate by sequestration and for nitrate to remain the same.

“With no sump and no skimmer, my struggle is to balance sufficient feeding without driving nitrates and phosphate too high. Water parameters are fine, except phosphate has been hovering between 0.2–0.35. With more frequent canister cleaning, and I just added a small bag of GFO, I believe my phosphates will be somewhat lower.”

Please list your nitrate ppm. I don’t know what fine water parameters means.

 

[Subsea]

See tank details in signature block. Tank is one year old, seven small fish, two Nems, a few softies and trying LPS, plus CUC.

With no sump and no skimmer, my struggle is to balance sufficient feeding without driving nitrates and phosphate too high. Water parameters are fine, except phosphate has been hovering between 0.2–0.35. With more frequent canister cleaning, and I just added a small bag of GFO, I believe my phosphates will be somewhat lower.

Reading this forum, I really want to add one bivalve to help consume some phosphate. Is that reasonable? If so, which particular creature would you suggest a newbie start with? I was initially leaning towards an oyster, but am learning a clam may be a safer first choice?

“Reading this forum, I really want to add one bivalve to help consume some phosphate. Is that reasonable? If so, which particular creature would you suggest a newbie start with? I was initially leaning towards an oyster, but am learning a clam may be a safer first choice?”

As a newbie with 1 year, I would not recommend a live oyster or live clam. For certain, it will not solve your phosphate number.

 

[MNscoe]

No to using a clam or an oyster to reduce only phosphate. If you are using GFO already, than switch to lanthanum chloride.

@MNscoe
While it’s true that clam biomass would have to include phosphate along with the nitrate, I have no idea what that ratio would be. In phytoplankton the N:P ratio is 16:1, in the macro algae Gracilaria Hayi the N:P ratio was 30:1 and in skimmate bacteria the N:P ratio is 5:1

Consider adding an HOB skimmer and carbon dose to export bacteria biomass.

If I read your post correctly, you just recently used GFO in your cannister filter for the first time. What else are you using for circulation in this 55G tank.

Not sure I understand your nutrient management. You want bivalves to reduce phosphate by sequestration and for nitrate to remain the same.

“With no sump and no skimmer, my struggle is to balance sufficient feeding without driving nitrates and phosphate too high. Water parameters are fine, except phosphate has been hovering between 0.2–0.35. With more frequent canister cleaning, and I just added a small bag of GFO, I believe my phosphates will be somewhat lower.”

Please list your nitrate ppm. I don’t know what fine water parameters means.

The answers and insights offered by everyone are some of the most helpful I've received on R2R Forums! Thank you all. I'm replying to @Subsea 's message but responding to all of you.

Yes, I just introduced 2 Tbsp of GFO last week for the first time, in the canister (Oase Biomaster Thermo 350). No other filtration, just a couple wavemakers. I'm just trying to slowly "nudge" my tank into healthier directions, and heard a bivalve or two could help when I don't have a skimmer.

Today nitrate is 25 and phosphate is 0.07, I attribute this lower P to a combination of water change, filter cleaning, and presumably the GFO.

@resortez Your memory of your tank, and your suggestions about tank residents and maintenance using a canister, made my day. Very encouraging and helpful, thank you!

@exnisstech This is my strategy -- to try establish an imperfect but stable tank, and then host whatever doesn't die when I put it in there...

Prompted by everyone's suggestions, I just learned that you can get HOB protein skimmers! -- I thought they only went in-tank or in-sump, neither of which would work for me. So now I'm shopping for one, people are suggesting the Aqua C Remora HOB or the Reef Octopus OCTO Classic 110-EXT.

And to modify my core question with this new info, I'd still like to try host a clam or oyster. @Tahoe61 suggests just buying one at the seafood store, and I'm game to start there (thanks!). But the pretty clams in the LFS are seductive, do you think I could keep a nice clam alive?
Thanks again everybody!

 

[Tahoe61]

For Tridacna, the giant clams it's all about lighting.
Clams and other mollusk are fascinating, and addictive.

 

[dloberry]

Do your research but keeping clams is attainable.

 

[Subsea]

“nitrate is 25 and phosphate is 0.07“


@MNscoe
Those numbers are good to go.

With respects to oysters & clams in your reef tank, the seafood market may work for you. However, consider getting them on diver collected live rock from the Gulf of Mexico.

 

[Lasse]

except phosphate has been hovering between 0.2–0.35

This 7 day ago

Yes, I just introduced 2 Tbsp of GFO last week for the first time, in the canister (Oase Biomaster Thermo 350). No other filtration, just a couple wavemakers. I'm just trying to slowly "nudge" my tank into healthier directions, and heard a bivalve or two could help when I don't have a skimmer.

Today nitrate is 25 and phosphate is 0.07, I attribute this lower P to a combination of water change, filter cleaning, and presumably the GFO.

This today

I´m sorry to say but I do not believe that 2 tablespoon of GFO will reduce your PO4 wirh more than 0.14 ppm - it make no sense. what do you use for PO4 measurements?

Sincerely Lasse

 

[MNscoe]

This 7 day ago

This today

I´m sorry to say but I do not believe that 2 tablespoon of GFO will reduce your PO4 wirh more than 0.14 ppm - it make no sense. what do you use for PO4 measurements?

Sincerely Lasse

@Lasse ,
My PO4 has been all over. I use a Hanna Phosphorus ULR and convert to PO4 value. But my reported range of 0.2-0.35 was not right, I'm not sure why I thought that, it's more 0.1 - 0.25.

I'll paste a chart (you may remember you helped me a year ago figure out my nitrogen cycle). The chart shows PO4 x100 so it graphs visibly on the same Y axis.

I think the big impact is water changes and canister filter cleanings, which I haven't been consistent about and am learning they can be big drivers of tank parameters. So now I'm working to do that better. What else could account for the big swings in PO4?

 

[Lasse]

Your average PO4 have rise since your trip - probably its your automatically feeding of dry food during this period a part of the reason. The swings - yest that´s another problem - I have seen it before with Hanna and these ULR analysis - I use the ULR phosphate method and it is driving me crazy sometimes with total incomprehensible oscillations. However . if it was long since you cleaned your sample tube - take some citric acid (At least in Sweden you can buy it from the grocery store) in the tube and fill with RO water. Let it be this way until you take next test. Rinse well with RO before use again. Nowadays I always store my sample tubes with a citric acid solution in them. Clean well. If you have much particles in the water - a 0.22 µ syringe filter is a good tool. I also clean my syringes with citric acid now and than.

I think the big impact is water changes and canister filter cleanings

This is interesting - do you see a rise or decrease of the PO4 concentration when you have cleaned the canister filter? How long do you normally run the canister filter between cleanings?

Sincerely Lasse

 

[MNscoe]

Your average PO4 have rise since your trip - probably its your automatically feeding of dry food during this period a part of the reason. The swings - yest that´s another problem - I have seen it before with Hanna and these ULR analysis - I use the ULR phosphate method and it is driving me crazy sometimes with total incomprehensible oscillations. However . if it was long since you cleaned your sample tube - take some citric acid (At least in Sweden you can buy it from the grocery store) in the tube and fill with RO water. Let it be this way until you take next test. Rinse well with RO before use again. Nowadays I always store my sample tubes with a citric acid solution in them. Clean well. If you have much particles in the water - a 0.22 µ syringe filter is a good tool. I also clean my syringes with citric acid now and than.


This is interesting - do you see a rise or decrease of the PO4 concentration when you have cleaned the canister filter? How long do you normally run the canister filter between cleanings?

Sincerely Lasse

I've heard the P ULR test can be very sensitive, and someone else mentioned storing their tubes in RODI at all times. I will work to clean them up (and the syringe) and see if it impacts anything.

I was cleaning the canister pre-filter every 2 weeks or so, and the main media sponges only every few months. It was pretty full of gunk this lsat time, partly because I've increased nori feeding to try help my Starry Blenny get some food from my food-protective bully of a BT Tang.

I've not monitored closely enough to correlate PO4 to canister cleanings. I'm going to be doing weekly pre-filter cleans now with weekly water changes, monthly media sponge cleans (in saltwater), and monthly change of my small GFO bag. My hope is this will keep the PO4 spikes down, and overall PO4 more stable at lower levels (<0.1 hopefully).

 

[SantaMonica]

I've not monitored closely enough to correlate PO4 to canister cleanings

You might try removing the canister altogether. Many times it's adding nutrients instead of removing them.