NP active pearls

Dear Dr tim
May I pose a question please,
My understanding of the use of NP pearls(biopellets)is to remove all phosphate and nitrates out of the system. I was under the impression that the zooxanthela in corals need phosphate and nitrates to feed on. So low levels are more desirable (nitrate 0.5-2ppm, phosphate 0.02-0.05ppm) than real zero levels. IF this is accurate then how would you modulate the effectiveness of the pellets in a fluid reactor since you need good flow to keep the media tumbling and maybe slower flow to control the effectiveness. Is there a reactor out there that can control both independently. Or am I simply over analyzing this.

Thank you for any clarification you may have.

Playb4work

 

Check out Reef Dynamics Bio Pellet reactors. they are a recirculating design similar to a calcium reactor. and they provide independent control over how your pellets tumble with adjustable effluent output.

I took this idea and applied it to a BRS media reactor and I have gotten the same effect.


Hope this answered your question.

 

low but not zero

Playbe4work

You are absolutely correct you do NOT want real zero levels and the truth is I doubt you would ever get there. The problem is that your impression is more than likely based upon what you have read which has been written by people who don't truly understand what is happening microbiologically in the aquarium.

There are two parts to your question:

First - using NP Pearls or pellets will NOT remove all the phosphate and nitrate. You need three things (I am simplifying here) to grow bacteria - carbon, nitrogen (nitrate) and phosphorus (phosphate) to grow bacterial cells. There is a general incorporation ratio of 50:10:1 (not the Redfield ratio) to these three (C:N: P). When one runs out the process basically stops. In our aquaria it is usually P that runs out. When that happens the process (bacterial growth) stops (well really slows down) leaving N.

In reality, what happens in the phosphate level will get very low, maybe even unmeasureable with your Hanna checker or test kit, and nitrate will be around 5 to 10 mg/L-N. I can't think of a case where both were zero in the same aquarium. But there are continuous inputs of nitrate and phosphate so more is always being added so the system enters a kind of steady state such that the coral bacteria get what they need and the bacteria on the pearls are ready to grab any excess and algae is kept in check. Things get out of balance when you increase the input of phosphate and nitrate by increasing the feed and so forth.

Now you may see corals stress when initially start with biopellets because the bacteria on the pellets grow faster and so take up phosphate and nitrate quickly when may not leave enough for the current load of symbiotic algae in the corals. That is why you start with a small amount of biopellets and work up to a larger volume.

The second part of your question

tredreef gave you a lead on one. But the real key is to make sure the pearls tumble and mix-up in the reactor which they do in the BashSea reactor we sell. Some reactors just seems to swirl the pearls which is not what you want. I would not get to caught up in trying to maintain some perfect mix of water flow and tumbling because I am not sure there is one - in our testing as long as the pearls are tumbling and mixing with each other they will work.

Cheers

 

Nice reply Doc

 

Wow! thanks Dr Tim, and Tredreef.

One more quick question, I have a refugium with macro algae (cheato), should I keep it or will it become useless after using the pearls.

Thanks again

 

I use ecobak not to conflict with brands of pellets here but my experience so far with them it keeps my nitrates around .25 or .5 and phosphates at 0 on my elos test kit. Seen almost no algae through cycle phases and still havent. Also i use a t on my drain 1 to skimmer/pellet section and one to refugium so my rerfugium gets unfiltered water. I run ulva and extra live rock and seen almost no growth yet on my algae to this point so I dont know if it would be useful for anything but maybe pods.

 

FatBastard - thanks

playb4work - I would keep it right now and maybe you can phase it out. It all depends on your inputs.

nwfd1725 - thanks for the experience. Can you tell us (and this goes for all who post) what are the units of your test kits or what test kits do you use. That way we can be talking apples to apples and not assume what units you mean.

Cheers

 

Red sea pro for Nitrate which I believe is PPM and Phosphate is Elos which I think is also PPM

 

Reading about the Red Sea Pro Nitrate test kit it seems to measure the nitrate ion. The number I talk about are nitrate measured as nitrogen. The conversion is about about 4.4 so your value of 0.25 to 0.5 NO3 is 1.1 - 2.2 NO3-N.

The Elos phosphate kit also seems to report in the ion form PO4(3-) rather than as Phosphorus the conversion here is 3.06 but you report a 0 value so it is pretty low. Not surprising since you have both pellet and a refugium. Do you use GFO?

Cheers

 

No gfo just refugium and bio pellets