Hi everyone! I need some advice and this is the best place in the world for high quality reef advice, so please bear with me and thanks in advance for your help!
Basically I was skimmerless for a couple of weeks after removing my previous skimmer to prepare the sump for a skimmer upgrade and observe how the tank would be skimmerless. Those two weeks have been the only two weeks I’ve ever been skimmerless, aside from the first couple of months after putting salt and water in my first reef tank (I was a broke college kid 16 years ago).
The reason for upgrading the skimmer was twofold; primarily because of a desire to get nutrients down from around 0.3 ppm PO4 and 15-20 ppm NO3. I felt my old skimmer was inadequate; plus I’m working on a new tank 4-5x the size of my current one and upgraded to a larger and “better model.” Now I have the Reef Octopus Regal 250EXT. Earlier I had the Red Sea RSK-300.
I’m now running the new skimmer and until yesterday hadn’t connected my CO2 scrubber. What I’ve seen is the macroalgae I have (multiple species but probably 80% chaeto) is suddenly not doing well and is rapidly wasting, and pH until yesterday was lower still (8.1-8.2) vs. no skimming (8.2-8.3) vs. my old skimmer with CO2 scrubbing (8.4-8.5). This suggested my new skimmer without scrubbing was almost certainly driving more CO2 from household air into the water column than would be coming in without skimming. So I’d imagined that would be a good thing for macroalgae.
Another point is that the easily measurable nutrients aren’t really low now either; still around .1 ppm PO4 and 10-15 ppm NO3. So it seems the macroalgae wasting away might not be related to lack of nutrients or lack of CO2.
I have a Kessil refugium light above the refugium and haven’t changed the lighting at all and also haven’t changed my dosing of anything. I plumbed the skimmer into the sump via a modified Triton approach but with recirculating water in the sump (skimmer feed pulls a portion of water post refugium to skimmer, and skimmer effluent goes back in before the refugium). This was due to space reasons mainly but certainly also has the effect of increasing local flow rate in the refugium.
My macroalgae is almost totally gone now. I hooked my CO2 scrubber back up yesterday though, as we’ve spent the weekend inside and pH was approaching 8, which I felt it was too low. Eighteen hours after reinstalling the scrubber, pH is back up to 8.5 as might be expected.
But the big question in my case is what’s messing with the macroalgae in such a huge way? I’m thinking it’s one or more of the following as other variables are unchanged, at least those variables I can think of. Too much flow through the refugium now? Nutrient issue? Or the new gas/liquid equilibrium is somehow impacting the algae?
I just plumbed the skimmer air intake outside vs. scrubbing and will see how things look after a few days. I’m considering what to test next if there’s no improvement; turning the skimmer off when refugium lights are on, or turning the skimmer off full time again.
I’m no fan of frequent changes, but if the macroalgae keeps wasting away at the present rate, I guess it will be gone before the end of this coming week. Not the end of the world, I can start over again, but still.
Thanks again in advance for you comments, thoughts, and advice!
Adam
Basically I was skimmerless for a couple of weeks after removing my previous skimmer to prepare the sump for a skimmer upgrade and observe how the tank would be skimmerless. Those two weeks have been the only two weeks I’ve ever been skimmerless, aside from the first couple of months after putting salt and water in my first reef tank (I was a broke college kid 16 years ago).
The reason for upgrading the skimmer was twofold; primarily because of a desire to get nutrients down from around 0.3 ppm PO4 and 15-20 ppm NO3. I felt my old skimmer was inadequate; plus I’m working on a new tank 4-5x the size of my current one and upgraded to a larger and “better model.” Now I have the Reef Octopus Regal 250EXT. Earlier I had the Red Sea RSK-300.
I’m now running the new skimmer and until yesterday hadn’t connected my CO2 scrubber. What I’ve seen is the macroalgae I have (multiple species but probably 80% chaeto) is suddenly not doing well and is rapidly wasting, and pH until yesterday was lower still (8.1-8.2) vs. no skimming (8.2-8.3) vs. my old skimmer with CO2 scrubbing (8.4-8.5). This suggested my new skimmer without scrubbing was almost certainly driving more CO2 from household air into the water column than would be coming in without skimming. So I’d imagined that would be a good thing for macroalgae.
Another point is that the easily measurable nutrients aren’t really low now either; still around .1 ppm PO4 and 10-15 ppm NO3. So it seems the macroalgae wasting away might not be related to lack of nutrients or lack of CO2.
I have a Kessil refugium light above the refugium and haven’t changed the lighting at all and also haven’t changed my dosing of anything. I plumbed the skimmer into the sump via a modified Triton approach but with recirculating water in the sump (skimmer feed pulls a portion of water post refugium to skimmer, and skimmer effluent goes back in before the refugium). This was due to space reasons mainly but certainly also has the effect of increasing local flow rate in the refugium.
My macroalgae is almost totally gone now. I hooked my CO2 scrubber back up yesterday though, as we’ve spent the weekend inside and pH was approaching 8, which I felt it was too low. Eighteen hours after reinstalling the scrubber, pH is back up to 8.5 as might be expected.
But the big question in my case is what’s messing with the macroalgae in such a huge way? I’m thinking it’s one or more of the following as other variables are unchanged, at least those variables I can think of. Too much flow through the refugium now? Nutrient issue? Or the new gas/liquid equilibrium is somehow impacting the algae?
I just plumbed the skimmer air intake outside vs. scrubbing and will see how things look after a few days. I’m considering what to test next if there’s no improvement; turning the skimmer off when refugium lights are on, or turning the skimmer off full time again.
I’m no fan of frequent changes, but if the macroalgae keeps wasting away at the present rate, I guess it will be gone before the end of this coming week. Not the end of the world, I can start over again, but still.
Thanks again in advance for you comments, thoughts, and advice!
Adam
