Wet Dry Plus Carbon Dosing > Skimmer

[GARRIGA]

I think it's pretty evident when you look at and smell a skimmer cup

When I ask myself, "Do I need a skimmer? Do I want that in my water?"

What the answers are

Thus I put the largest skimmer that will fit

Smell because decomposition not allowed to handle it.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I have recently been recommending against any use of media that promotes nitrification due to making it harder for corals to attain the N they need.

 

[InvoluntaryReefer]

Ditto on the Salinity problem, but discovered this was more caused by fluctuation in the return and downpipe from the main display overflow.

One of the below would happen:
Overflow downpipe would slow down flow to the sump, causing the ATO to dump.
Return would randomly speed up enough to slowly pull more water from the dump than the downpipe could replace causing the ATO to dump.
A rogue wave caused by randomization in the wave makers would cause more water to enter the overflow than normal flooding the sump and cause the skimmer to overskim. RedSea's auto-cut off sensor wasn't as reliable as I hoped or would overcorrect.
Return would slow down for enough (not out of norm, but enough) to cause sump to flood.

All the above was when the sump was just a plain old sump system:
Tried all types of micron socks (felt, mesh, etc.)
ReefMatt.
RedSea 300 (eventually replaced with the new version).

As I grew frustrated:
Disassembled the Reefmatt threw in the corner in a fit of rage.
Removed the sponge before the return.
Replaced the socks with cups.

Fast forward 2 years later

I rarely use a skimmer or carbon media. I do ensure there is a significant drop from main sump to return to build up some gas. I don't use filter socks, I just use the plastic cups from RedSea. Occasionally I will run the skimmer if I am trying to make the tank look clearer, but I'll usually just add a little extra PNS or Microbacter. PO3 reducer on the occasion. I have more of an issue keeping nitrates and phosphates levels up and consistent. No biofilm build up on the surface of the sump unless I really double up dosage of Carbon Dosing (BioReef).

I dose:
1-3 drops of Oysterfeast.
1-3 drops of live-phyto.
Cap of BioReef (Carbon).
HydroSpace PNS 10-20ml + Microbacter 7 5ml (mainly to keep some biofilm on the rocks in the main display for the starfish).
Use Soda Ash for Alk.

Initially, the hardest part was keeping PH consistent -
Switching to Soda Ash for Alk helped stabilize it.

Sump:
Full of sand, standard white lighting, rock all-over, a Saddle Valentini puffer (Puff), pencil urchin, crabs, a lobster, pest starfish, six-line wrasse, various NPS, and Hawkfish.

Main display:
LPS, SPS, NPS, and Anenome. More sand/rock, at 64 Gallons, 6 fish, a huge booty seahare, 2 starfish, pincusion urchin, emerald crabs, staghorn crabs, gallons worth of pods, and 70-80+ coral.

 

[GARRIGA]

FWIW, I have recently been recommending against any use of media that promotes nitrification due to making it harder for corals to attain the N they need.

We discussed this before where I pointed out corals have first access to nutrients before it exits the display and gets processed. Wouldn’t the solution be to increase nutrients thereby increase contact and especially since some like myself like to have a higher bio load of fish and starting with frags means natural filtration by corals might be years before system mature enough to resolve waste produced.

 

[GARRIGA]

Ditto on the Salinity problem, but discovered this was more caused by fluctuation in the return and downpipe from the main display overflow.

One of the below would happen:
Overflow downpipe would slow down flow to the sump, causing the ATO to dump.
Return would randomly speed up enough to slowly pull more water from the dump than the downpipe could replace causing the ATO to dump.
A rogue wave caused by randomization in the wave makers would cause more water to enter the overflow than normal flooding the sump and cause the skimmer to overskim. RedSea's auto-cut off sensor wasn't as reliable as I hoped or would overcorrect.
Return would slow down for enough (not out of norm, but enough) to cause sump to flood.

All the above was when the sump was just a plain old sump system:
Tried all types of micron socks (felt, mesh, etc.)
ReefMatt.
RedSea 300 (eventually replaced with the new version).

As I grew frustrated:
Disassembled the Reefmatt threw in the corner in a fit of rage.
Removed the sponge before the return.
Replaced the socks with cups.

Fast forward 2 years later

I rarely use a skimmer or carbon media. I do ensure there is a significant drop from main sump to return to build up some gas. I don't use filter socks, I just use the plastic cups from RedSea. Occasionally I will run the skimmer if I am trying to make the tank look clearer, but I'll usually just add a little extra PNS or Microbacter. PO3 reducer on the occasion. I have more of an issue keeping nitrates and phosphates levels up and consistent. No biofilm build up on the surface of the sump unless I really double up dosage of Carbon Dosing (BioReef).

I dose:
1-3 drops of Oysterfeast.
1-3 drops of live-phyto.
Cap of BioReef (Carbon).
HydroSpace PNS 10-20ml + Microbacter 7 5ml (mainly to keep some biofilm on the rocks in the main display for the starfish).
Use Soda Ash for Alk.

Initially, the hardest part was keeping PH consistent -
Switching to Soda Ash for Alk helped stabilize it.

Sump:
Full of sand, standard white lighting, rock all-over, a Saddle Valentini puffer (Puff), pencil urchin, crabs, a lobster, pest starfish, six-line wrasse, various NPS, and Hawkfish.

Main display:
LPS, SPS, NPS, and Anenome. More sand/rock, at 64 Gallons, 6 fish, a huge booty seahare, 2 starfish, pincusion urchin, emerald crabs, staghorn crabs, gallons worth of pods, and 70-80+ coral.

My concern with skimmers has always been that water gets thrown out with the skimmate. Obviously how dry or wet one runs there skimmer impacts this but regardless water is being thrown out. For the no WC crowd as myself that’s a major concern.

This assumes skimmer not just used for gas exchange and to mechanically remove organics although guessing that with just gas exchange one still has to deal with some salt creep

 

[Randy Holmes-Farley Verified Community Expert]

We discussed this before where I pointed out corals have first access to nutrients before it exits the display and gets processed. Wouldn’t the solution be to increase nutrients thereby increase contact and especially since some like myself like to have a higher bio load of fish and starting with frags means natural filtration by corals might be years before system mature enough to resolve waste produced.

I do not actually know the typical lifetime of ammonia in reef tanks, and how many times it might pass through various aspects of the system.

 

[InvoluntaryReefer]

I do not actually know the typical lifetime of ammonia in reef tanks, and how many times it might pass through various aspects of the system.

Would be dependent on the population in the reef tank. Check out this article:
https://reefbuilders.com/2024/03/06/is-ammonia-dosing-a-possible-new-way-to-provide-coral-nutrition/

 

[Subsea]

My concern with skimmers has always been that water gets thrown out with the skimmate. Obviously how dry or wet one runs there skimmer impacts this but regardless water is being thrown out. For the no WC crowd as myself that’s a major concern.

This assumes skimmer not just used for gas exchange and to mechanically remove organics although guessing that with just gas exchange one still has to deal with some salt creep

I don’t use skimmers because they remove bacteria & microbes that feed corals & numerous other filter feeders, including ornamental sponges, in my display tank.

My 25 year mature 75G display tank was bought used with a 30G mud/algae refugium and it had a wet/dry section, then a mud filter on bottom with macro algae above. Five years ago, I removed seaweed, turned off the lights and added live rock inoculated with cryptic sponges.

 

[Randy Holmes-Farley Verified Community Expert]

Would be dependent on the population in the reef tank. Check out this article:
https://reefbuilders.com/2024/03/06/is-ammonia-dosing-a-possible-new-way-to-provide-coral-nutrition/

Yes, it would. But it is still not known. I do recommend dosing ammonia, as noted in the article.

 

[GARRIGA]

I don’t use skimmers because they remove bacteria & microbes that feed corals & numerous other filter feeders, including ornamental sponges, in my display tank.

My 25 year mature 75G display tank was bought used with a 30G mud/algae refugium and it had a wet/dry section, then a mud filter on bottom with macro algae above. Five years ago, I removed seaweed, turned off the lights and added live rock inoculated with cryptic sponges.

Seems odd that skimmers are recommended during carbon dosing to remove excess bacteria yet not often considered what affect they have on other microbes that may be beneficial. Having said that, ran skimmerless 2.5 plus years and often overdosed carbon so go figure. Lots of anecdotal that just gets repeated without foundation to support it.

 

[Randy Holmes-Farley Verified Community Expert]

Seems odd that skimmers are recommended during carbon dosing to remove excess bacteria yet not often considered what affect they have on other microbes that may be beneficial. Having said that, ran skimmerless 2.5 plus years and often overdosed carbon so go figure. Lots of anecdotal that just gets repeated without foundation to support it.

What do you consider a beneficial bacteria that is in the bulk water? I agree they can be good food for corals.

 

[Scott Campbell]

I've not found denitrification easy to achieve in a tank. Certainly not with a wet/dry system. Nitrification is helpful if you are concerned about overly high levels of ammonia - but that is rarely an issue in a tank full of corals. In a heavily stocked fish only tank I can see a wet/dry system being useful.

But nitrification is not going to remove any excess nutrients from the tank. If I have to choose between manually removing organic material from my tank or allowing it to be taken up by bacteria and then skimmed out of the aquarium - I would choose the skimmer approach to waste removal 100% of the time. Just so much easier. And honestly, a skimmer is fairly simple to operate. And the small amount of water removed seems trivial. Especially compared to the changes in salinity caused by dosing calcium chloride and sodium bicarbonate. I adjust for increasing salinity with regular small water changes. Small water changes are also helpful for a number of reasons. Carbon dosing in conjunction with a skimmer also allows you to increase nutrient export if needed. And the extra bacteria created by carbon dosing are enjoyed by the corals. I just don't see many benefits to a filtration system designed to simply convert ammonia to nitrate for a tank stocked with corals looking for ammonia.

 

[Scott Campbell]

I don’t use skimmers because they remove bacteria & microbes that feed corals & numerous other filter feeders, including ornamental sponges, in my display tank.

My 25 year mature 75G display tank was bought used with a 30G mud/algae refugium and it had a wet/dry section, then a mud filter on bottom with macro algae above. Five years ago, I removed seaweed, turned off the lights and added live rock inoculated with cryptic sponges.

I largely agree. My tank is packed with sponges and I believe they are enormously helpful. And I do believe there is a benefit to carbon dosing to create extra bacterial food for the corals. But I also have no clue what strains of bacteria my corals feed on. And my feeling is that the corals will grab any desired bacteria out of the water column as effectively, if not more effectively, than my skimmer. So I'm not really concerned about the skimmer pulling out what appears to be extra bacteria or bacteria not especially desired by my particular corals. I think you are underestimating corals in thinking the skimmer would beat them to the mark on desirable bacteria.

And as much as I love sponges - sponges are also not a perfect nutrient export mechanism. They can filter DOC out of the water and aid in the removal of carbon waste from the system. But you will still need some other form of export (algae scrubber, water changes, skimmer, etc.) to remove nitrate and phosphate. And skimmers are a great and rather natural way to deal with this export. And there is really no reason why you couldn't have both cryptic sponges and a skimmer. It is not really an either/or decision.

 

[GARRIGA]

What do you consider a beneficial bacteria that is in the bulk water? I agree they can be good food for corals.

Don’t know and beyond my knowledge but understand corals will filter the water and assume some of that likely being stripped by skimming. Being most rely on skimmers then perhaps one of those things we won’t know because not enough anecdotal data supported by those not skimming yet I go back to the fact corals filter the water and many feed it into phyto therefore thinking safe to assume they feed on other particulates found in most tanks. Including potentially that produced by sponges. Another topic beyond my scope but I’m trying.

 

[Subsea]

I largely agree. My tank is packed with sponges and I believe they are enormously helpful. And I do believe there is a benefit to carbon dosing to create extra bacterial food for the corals. But I also have no clue what strains of bacteria my corals feed on. And my feeling is that the corals will grab any desired bacteria out of the water column as effectively, if not more effectively, than my skimmer. So I'm not really concerned about the skimmer pulling out what appears to be extra bacteria or bacteria not especially desired by my particular corals. I think you are underestimating corals in thinking the skimmer would beat them to the mark on desirable bacteria.

And as much as I love sponges - sponges are also not a perfect nutrient export mechanism. They can filter DOC out of the water and aid in the removal of carbon waste from the system. But you will still need some other form of export (algae scrubber, water changes, skimmer, etc.) to remove nitrate and phosphate. And skimmers are a great and rather natural way to deal with this export. And there is really no reason why you couldn't have both cryptic sponges and a skimmer. It is not really an either/or

I largely agree with one caveat on sponge loop:

Cryptic sponges and ornamental sponges are not the same while both are opportunistic with what they consume.

Cryptic sponges consume DOC & POC at such a rate they would double in size in 20 minutes but for the carbon rich detritus that they slough off. This carbon rich detritus is food for the microbial loop which feeds diverse filter feeders including NPS & corals, flame scallops, sea apples and ornamental as well as cryptic sponges.


And one caveat on nutrient export:

(And as much as I love sponges - sponges are also not a perfect nutrient export mechanism. But you will still need some other form of export (algae scrubber, water changes, skimmer, etc.) to remove nitrate and phosphate.)

I don’t use ornamental sponges for nutrient export: they look pretty and they filter out more than bactetia. How about microbes, viruses and pathogens like ich.

More importantly, I use cryptic sponges for nutrient recycling.

For nutrient export; I sell sponges, corals and ornamental seaweeds.

 

[Scott Campbell]

I largely agree with one caveat on sponge loop:

Cryptic sponges and ornamental sponges are not the same while both are opportunistic with what they consume.

Cryptic sponges consume DOC & POC at such a rate they would double in size in 20 minutes but for the carbon rich detritus that they slough off. This carbon rich detritus is food for the microbial loop which feeds diverse filter feeders including NPS & corals, flame scallops, sea apples and ornamental as well as cryptic sponges.


And one caveat on nutrient export:

(And as much as I love sponges - sponges are also not a perfect nutrient export mechanism. But you will still need some other form of export (algae scrubber, water changes, skimmer, etc.) to remove nitrate and phosphate.)

I don’t use ornamental sponges for nutrient export: they look pretty and they filter out more than bactetia. How about microbes, viruses and pathogens like ich.

More importantly, I use cryptic sponges for nutrient recycling.

For nutrient export; I sell sponges, corals and ornamental seaweeds.

Agree 100%. For 35+ years I have just dumped everything straight into the tank without ever quarantining. Have never once seen Ich on even a single fish. Which I credit entirely to the sponges in the tank. As you note - sponges are also amazing at nutrient recycling.

That you are able to handle your nutrient export by selling sponges, corals and seaweed is incredible. I am duly impressed. Very cool.

 

[Subsea]

Agree 100%. For 35+ years I have just dumped everything straight into the tank without ever quarantining. Have never once seen Ich on even a single fish. Which I credit entirely to the sponges in the tank. As you note - sponges are also amazing at nutrient recycling.

That you are able to handle your nutrient export by selling sponges, corals and seaweed is incredible. I am duly impressed. Very cool.

Thank you for kind words. After 55 years of Reefing, I keep it simple.