Bio pellets vs Refugium (Flow Rate)

[MantisShrimpMan]

How do you determine the correct flow rate for a biopellet reactor, how do you determine the ideal flow rate for a refugium, and is there any chance those two could be compatible?

I’d like to add a Clear Tides HOB refugium to my 20G AIO. Their refugiums have the option to include a vertical tube around the inlet, turning the front end of the flow into a media reactor.

I’m currently a broke college student, and my goal with this AIO has been “use it to learn as much as you can about reefkeeping before your eventual upgrade to a proper sump‘d system once you’re outta school” So this would give me firsthand experience with a media reactor, which is practically never seen in most smaller AIO systems. So I’d like to take that a step further by using this as an opportunity to gain firsthand experience with biopellets. I’ve been tempted by the KZ zeovit system for a while but that seems a bit too impractical for this particular application, whereas I think biopellets could work.

The issue is- could I push enough flow through this system to get the biopellets tumbling the way they’re supposed to? And, if I were to do that, would it end up pushing too much flow through my refugium? The return pump that this thing comes with is rated for 350 liters/hour or 92 gph. I believe the necessary flow for biopellet tumbling to be dependent upon the size of the reactor (its gonna need more flow to get twice the amount of biopellets all tumbling) but still, the lowest number I found on google was 150gph, and most suggestions were up at 200gph+. For the sake of this hypothetical you can dismiss any concerns that are specific to the return pump shown in the pic. Assuming I were to get a larger pump to get the media tumbling, would I then be putting too much flow through my refugium?

 

[Dan_P]

How do you determine the correct flow rate for a biopellet reactor, how do you determine the ideal flow rate for a refugium, and is there any chance those two could be compatible?

I’d like to add a Clear Tides HOB refugium to my 20G AIO. Their refugiums have the option to include a vertical tube around the inlet, turning the front end of the flow into a media reactor.

I’m currently a broke college student, and my goal with this AIO has been “use it to learn as much as you can about reefkeeping before your eventual upgrade to a proper sump‘d system once you’re outta school” So this would give me firsthand experience with a media reactor, which is practically never seen in most smaller AIO systems. So I’d like to take that a step further by using this as an opportunity to gain firsthand experience with biopellets. I’ve been tempted by the KZ zeovit system for a while but that seems a bit too impractical for this particular application, whereas I think biopellets could work.

The issue is- could I push enough flow through this system to get the biopellets tumbling the way they’re supposed to? And, if I were to do that, would it end up pushing too much flow through my refugium? The return pump that this thing comes with is rated for 350 liters/hour or 92 gph. I believe the necessary flow for biopellet tumbling to be dependent upon the size of the reactor (its gonna need more flow to get twice the amount of biopellets all tumbling) but still, the lowest number I found on google was 150gph, and most suggestions were up at 200gph+. For the sake of this hypothetical you can dismiss any concerns that are specific to the return pump shown in the pic. Assuming I were to get a larger pump to get the media tumbling, would I then be putting too much flow through my refugium?

The basic idea I think is to determine have much flow is needed to pass 99% of the system’s water through a device in say 12 hours. I don’t know the formula off hand but the number is larger than total volume divided by flow rate because the untreated water is diluted by treated water every pass through the device. This means it takes longer than you think to process all the “dirty” water.

That being said, I would not worry about pushing water too quickly through a refugium. Algae benefit from flow. So tumble the pellets and let the refugium tumble too. Unless you are shredding the algae, life should be good, even cyanobacteria free.

 

[Randy Holmes-Farley]

FWIW, I'm not a huge fan of biopellets. Much harder to adjust easily (in amount and in timing) compared to dosing liquid organics such as vinegar. That said, I do not know the best ways to implement them.

 

[MantisShrimpMan]

FWIW, I'm not a huge fan of biopellets. Much harder to adjust easily (in amount and in timing) compared to dosing liquid organics such as vinegar. That said, I do not know the best ways to implement them.

I’ve also considered running zeo, thoughts on that?

 

[Randy Holmes-Farley]

I’ve also considered running zeo, thoughts on that?

I'm not a fan of the pastel color look of typical zeovit aquaria, if you mean the full method.

Aside from that, I do not like dosing secret concoctions.

But there certainly are people who like and continue to use the method.

 

[MantisShrimpMan]

I'm not a fan of the pastel color look of typical zeovit aquaria, if you mean the full method.

Aside from that, I do not like dosing secret concoctions.

But there certainly are people who like and continue to use the method.

wait so I tried vodka dosing for month and never saw the results, plus I want my tank to be semi low maintenance and I can’t afford dosing pumps quite yet. Why don’t you like biopellets

 

[Randy Holmes-Farley]

wait so I tried vodka dosing for month and never saw the results, plus I want my tank to be semi low maintenance and I can’t afford dosing pumps quite yet. Why don’t you like biopellets

I expect you just didn't add enough. I cannot see it not working in the nutrient sense if you add enough and wait a bit, as long as you don't have to stop for some other reason, such as increased cyanobacteria. We have a whole advanced thread on why it sometimes takes a long time to see nitrate drop, and IMO, the leading theory is not enough being dosed early on. It's not like some Diety flawlessly deemed how much one should dose.

I dislike biopellets for the reasons I stated:

1. It is hard to control the "dose". It's much easier to increase or decrease liquid dosing every day, as desired.

2. All organic carbon dosing (liquid or solid) lowers pH (unless it contains a high pH alk supplement in it) and O2. I prefer to see that happen during the peak of O2 and pH during the day, and it is easy to dose liquids to attain that, while quite tricky with pellets.

 

[MantisShrimpMan]

I expect you just didn't add enough. I cannot see it not working in the nutrient sense if you add enough and wait a bit, as long as you don't have to stop for some other reason, such as increased cyanobacteria. We have a whole advanced thread on why it sometimes takes a long time to see nitrate drop, and IMO, the leading theory is not enough being dosed early on. It's not like some Diety flawlessly deemed how much one should dose.

I dislike biopellets for the reasons I stated:

1. It is hard to control the "dose". It's much easier to increase or decrease liquid dosing every day, as desired.

2. All organic carbon dosing (liquid or solid) lowers pH (unless it contains a high pH alk supplement in it) and O2. I prefer to see that happen during the peak of O2 and pH during the day, and it is easy to dose liquids to attain that, while quite tricky with pellets.

On point number 2, here’s what I’m wondering about. Can chaeto survive in still water for part of the day? If so, could I turn on the pump to the HOB refugium at the same time I turn on the light? I know people run refugium lights at night so they mitigate pH swings. Assuming I keep my flow either off or at a low trickle during the day, then come the night I turn on the refugium pump and the light, that means that the biopellets are only really being given the chance to lower the pH during the night, which is when my chaeto would be raising it. Wouldn’t a good chunk of chaeto or any other macro work to cancel that out? Assuming you have the same amount of chaeto one way or the other, it would certainly reduce the impact of the Chaeto’s ability to keep pH high, but I’d assume the chaeto does more to raise the pH than the biopellets do to lower it? And would chaeto survive if left in still water for 12 hours a day? Do you know of any return pumps aside from the Neptunes that would allow me to run them at like 50 gph for half the day and 200 gph for the other half?

Also, can you send me whatever evidence there is that biopellets lower pH? I’m a biomedical engineering student and I’d like to understand the science behind this stuff.

Lastly, my apologies but I don’t entirely understand to what severity you are claiming that biopellets are flawed in relation to liquid dosing. There are plenty of things in reefing that are more ideal than something else, but the degree to which they are more ideal varies. like, an improper heater is so much worse than a good one because the minute it decides to crap out and cook your tank, your tank crashes. But, say, the difference between a Hanna colorimeter and an API test kit. Hanna is gonna be easier to trust the exact results on compared to the color charts, but the color charts are at least going to put you within the feasible range to not crash your tank. So I guess what I’m getting at is that some disparities in solution viability can make the difference between a tank crash, and others are just more minor improvements to system stability. I’m having trouble telling where you’d rate biopellets in that regard. Would you still consider them viable in maintaining a proper reef tank, just less preferable than vodka dosing? Or would you go as far as to say that you cannot achieve as impressive results with solid forms of carbon dosing as you can with the liquid forms?

Also, I just gotta say, I’ve read your articles and i idolize you @Randy Holmes-Farley . It’s so freaking cool that you apply upper level chemistry to reefkeeping. If you have any articles on the specifics that drive your beliefs behind carbon dosing, please send them my way.

 

[Randy Holmes-Farley]

Also, can you send me whatever evidence there is that biopellets lower pH? I’m a biomedical engineering student and I’d like to understand the science behind this stuff.

That part is easy. Metabolism of any neutral organic produces CO2, which lowers pH.
I can post the balanced reaction tomorrow.

 

[MantisShrimpMan]

That part is easy. Metabolism of any neutral organic produces CO2, which lowers pH.
I can post the balanced reaction tomorrow.

Ahh i didn’t even take the time to think through that, but I should have, that makes sense. As for the other stuff, what do you think?

Also, on an unrelated note, considering you have a massive background in reefkeeping and dosing, do you have any favorites for dosing pumps?

 

[Randy Holmes-Farley]

Ahh i didn’t even take the time to think through that, but I should have, that makes sense. As for the other stuff, what do you think?

Also, on an unrelated note, considering you have a massive background in reefkeeping and dosing, do you have any favorites for dosing pumps?

I've never looked deeply into dosing pumps. I used the BRS 1.1 mL per minute pumps for many things.

I'd be careful about ever stopping flow of reef tank water in tubing etc. for fear that bacteria in it may consume organics, driving down O2 and possibly making hydrogel sulfide.

 

[Zeeter]

<snip>

The issue is- could I push enough flow through this system to get the biopellets tumbling the way they’re supposed to? And, if I were to do that, would it end up pushing too much flow through my refugium?

There's a growing movement on using a refugium OR biopellets. The issue is that the two will fight for nutrients and neither will be successful, or one will be successful while the other is useless.

What usually happens is that the refugiums are simply not big enough in most tanks to be worthwhile. In this case, a half-gallon refugium with chaeto isn't going to do a whole lot while the biopellets likely will.