Thoughts on over skimming

[sphelps]

Originally Posted by StirCrazy

I severly overskim my tanks and got fantastic results, remember if you are over skimming you have to pay closer attention to your water peramiters, and make sure your compensate your feeding, ie feed more often or feed more as good skimming will remove waist food faster.

I had LPS and SPS, worms, Pods. which thrived in my overskimmed tanks, and had to scrape coraline algae off the glass every day, so I don't think overskiming is your problem as much as water peramiters/light/ect.

My Brain grew from a 3" base to a 6" base in about 6 months, mushroom became such a problem I had to remove them as they were taking over, and SPS gave me amazing growth rates.. all while using a skimmer that was probably rated for 6X the system volume of water. I ran the skimmer so it made a fairly dry foam, ran a Co2 reactor, Kalk reactor, sever water flow (aprox 120X turnover) but I did run a slightly elivated Alk, I liked 1.026 for salinity, 11 to 12Dkh, about 380 to 400 Ca, 1400 Mg, and my Ph was always around 7.9 I ran two AB 10K SE bulbs driven by M80 ballasts on a 3 foot tank plus two 3 foot VHO actinic bulbs overdriven about 14%. the tank was bare bottom, but I built Pod piles behind the rock work. I find the bigest mistake people make is not building pod piles as this gives them a place to grow with out worry of preditation. I had two mandrins and they always were eating pods which I feel was due to the pod piles as they mandrens can't get into them, so the pods can reproduce like mad and as the populatin increases they spread through out the tank.

Steve

What water parameters are you referring to? Anything I can test seems fine and I do 10% weekly water changes with RB salt. I don't have heavy light in my tank and I keep my LPS lower or in shady areas. The LPS did fine at first but lately a decrease in health in some is obvious.

From my experience higher nutrients results in healthier LPS, my first reef tank was an LPS tank, basically skimmerless and I never fed them, never have I had LPS corals as healthy as they were in that tank.



I'm willing to sacrifice some SPS color for healthier LPS, i would actually prefer to keep a more LPS dominant tank. Can any one see any potential problems resulting from running a skimmer on a half duty cycle over night?

[mr.wilson]

Low nutrient levels will cause a decline in LPS health, but it is not necessarily caused by your protein skimmer. It is more likely an issue tied to nutrient export such as water changes, algae harvesting, and other chemical filtration methods like carbon and ion exchange resins.

LPS & SPS don't readily mix in nature, so our expectations are generally over-optimistic when it comes to a mixed captive reef. Target feeding may be the only compromise of supply and demand.

There is some debate whether or not carbon is the limiting factor for coral health and growth. My guess is that carbon dosing fosters the growth of microorganisms that feed corals and consume nutrients, rather than bacteria that consume nutrients.

[sphelps]

Originally Posted by mr.wilson

Low nutrient levels will cause a decline in LPS health, but it is not necessarily caused by your protein skimmer. It is more likely an issue tied to nutrient export such as water changes, algae harvesting, and other chemical filtration methods like carbon and ion exchange resins.

LPS & SPS don't readily mix in nature, so our expectations are generally over-optimistic when it comes to a mixed captive reef. Target feeding may be the only compromise of supply and demand.

There is some debate whether or not carbon is the limiting factor for coral health and growth. My guess is that carbon dosing fosters the growth of microorganisms that feed corals and consume nutrients, rather than bacteria that consume nutrients.

Well i don't run carbon so would you consider running the skimmer at 0.5 duty, cutting water changes to 5% weekly and preventing algae growth a good initial approach to the problem?

[mr.wilson]

I don't see a problem with cutting back on protein skimming hours, especially if you don't have nuisance algae problems or high nutrient levels. If the LPS that you want to focus on are night feeders like Acanthastrea & Lobophyllia then maybe skimming during the day will be better for SPS and not skimming at night will offer more available food for night feeding LPS.

What are your nitrate and phosphate levels now? While protein skimmers are very efficient at removing protein, they will allow heavy metals to accumulate. If your nutrient levels are above zero, it's possible that the LPS are adversely affected by heavy metal accumulation.

The other approach would be to maintain your filtration as is, and do more indirect feeding with Phytoplankton.

[sphelps]

I thought about skimming in the day for that reason but I'm worried about oxygen levels dropping too low overnight. My powerheads slow down at night and my return is herbie style.

Those levels are not detectable with my test kits.

[mr.wilson]

How low does your PH drop at night. Your tank is well stocked so there must be significant coral respiration at night that would add a lot of Co2. A reverse photoperiod refugium would keep your nightly dissolved oxygen rates high and balance PH if that in fact is an issue.

I have mixed feelings about cutting back flow at night. On one hand it replicates natural reef conditions and allows plankton to get around better at night, but on the other hand it may lower dissolved oxygen, make it harder to off-gas Co2, and higher flow may be better for feeding extended night feeders.

Whatever you are doing right to keep phosphate and nitrate at zero appears to be great for your SPS, and not so good for LPS. I would guess that it's the low nutrients and not high toxic metal concentrations that are limiting LPS success.

Rather than limit what you are doing right (nutrient reduction & export through protein skimming and water changes), I would increase nutrient import with Phytoplankton, rotifers and whatever you prefer to feed. I've read a few threads on RC about dosing phosphate and nitrate, but I think they should be added via food, not chemically.

[sphelps]

Originally Posted by mr.wilson

How low does your PH drop at night. Your tank is well stocked so there must be significant coral respiration at night that would add a lot of Co2. A reverse photoperiod refugium would keep your nightly dissolved oxygen rates high and balance PH if that in fact is an issue.

I have mixed feelings about cutting back flow at night. On one hand it replicates natural reef conditions and allows plankton to get around better at night, but on the other hand it may lower dissolved oxygen, make it harder to off-gas Co2, and higher flow may be better for feeding extended night feeders.

Whatever you are doing right to keep phosphate and nitrate at zero appears to be great for your SPS, and not so good for LPS. I would guess that it's the low nutrients and not high toxic metal concentrations that are limiting LPS success.

Rather than limit what you are doing right (nutrient reduction & export through protein skimming and water changes), I would increase nutrient import with Phytoplankton, rotifers and whatever you prefer to feed. I've read a few threads on RC about dosing phosphate and nitrate, but I think they should be added via food, not chemically.

I updated the firmware on my controller the other day which seems to have reset the stored calibration numbers, I need to recalibrate to get a more recent reading but I believe it drops to around 7.8 but will check later.

I know what you mean about the lower flow at night but the power heads only cut back to 30% so they still move a little water and i still have 10X through the return I mainly cut it back because it makes a little quiet time for the seahorse which takes full opportunity to come out and swim a little each night.
I'm not really into the refugium thing right now, I'm trying to keep things simple and clean with this tank and I think the it will create more complication than benefit. Personally I think running the skimmer at night might be a better option than the day. The skimmer is also the only part of the tank that makes any real noise, if the only time it's on is when I'm sleeping I can see that itself being a significant benefit.

I can always turn the skimmer off while I'm feeding. During feeding of any sort I always activate a feeding pause which shuts off everything for 20min, and the skimmer has an additional delay of 30min.

I'm going to experiment and shut the skimmer off during the day, it's large enough that I don't see the need for it anyway and I can always turn it back on at anytime. I'll cut back water changes, work on the algae, feed more and try dosing some stuff like phyto (live or processed btw??) and some zeo products.

[StirCrazy]

Originally Posted by sphelps

I don't have heavy light in my tank and I keep my LPS lower or in shady areas. The LPS did fine at first but lately a decrease in health in some is obvious.

From my experience higher nutrients results in healthier LPS, my first reef tank was an LPS tank, basically skimmerless and I never fed them, never have I had LPS corals as healthy as they were in that tank.


I'm willing to sacrifice some SPS color for healthier LPS, i would actually prefer to keep a more LPS dominant tank. Can any one see any potential problems resulting from running a skimmer on a half duty cycle over night?

the first thing that pops out to me is "I don`t have heavy light in my tank".

the reason this is jumping out at me is you have to think of LPS like SPS but more flesh. yes they will do good under low light if they are fed, but when you are skimming heavily how are they getting fed? when you have intense lighting just like a SPS they will expell symbiotic algae as they don't need as many to create food for them other wise they need food by being fed directly or by adsorbing it from the water colum.. if you don't target feed frequently, or like dirty water then you need enough light to sustain them. take my open brain as an example.. when I was running PS and VHO he was about 3" dia at the base (6" when expanded) and would eat 1 or 2 krill a day as I upgraded the lighting he started taking less food then it got to the point I could put mysis all over him and he wouldn't feed, but he kept growing and getting more color. when I had the tank melt down (heater got stuck on in a temp tank when I was removing the sand bed) he had a skeliton of 6 to 7" dia and would be almost 14" when expanded but he hadn't taken food in over 6 months. I could only conclude that he was getting all the food he needed from his internal algae and the lights.

so would I recomend overskimming with lower light power.. nope, you want crystal clean water you need plenty of light power.

Steve

[sphelps]

Originally Posted by StirCrazy

the first thing that pops out to me is "I don`t have heavy light in my tank".

the reason this is jumping out at me is you have to think of LPS like SPS but more flesh. yes they will do good under low light if they are fed, but when you are skimming heavily how are they getting fed? when you have intense lighting just like a SPS they will expell symbiotic algae as they don't need as many to create food for them other wise they need food by being fed directly or by adsorbing it from the water colum.. if you don't target feed frequently, or like dirty water then you need enough light to sustain them. take my open brain as an example.. when I was running PS and VHO he was about 3" dia at the base (6" when expanded) and would eat 1 or 2 krill a day as I upgraded the lighting he started taking less food then it got to the point I could put mysis all over him and he wouldn't feed, but he kept growing and getting more color. when I had the tank melt down (heater got stuck on in a temp tank when I was removing the sand bed) he had a skeliton of 6 to 7" dia and would be almost 14" when expanded but he hadn't taken food in over 6 months. I could only conclude that he was getting all the food he needed from his internal algae and the lights.

so would I recomend overskimming with lower light power.. nope, you want crystal clean water you need plenty of light power.

Steve

I've experimented with a few of my LPS and moved them in brighter light and they would show signs of bleaching and when moved back into lower light would color back up. I think the problem is beyond lighting. It's not heavy lighting but it's not dim either; 2 x 250W DE 14K Phoenix run on HQI and two 54W 22K T5s.

Steve what are you using for a skimmer and what size tank and bio-load? Maybe you're not over skimming as much as me, my bio-load is quite small, 5 fish and I also have 3 large clams (not that there necessarily doing much nutrient export). My skimmer is rated for 250-750 gallon aquariums, having a larger skimmer is good but I'm starting to think mine is just too big.