Prestigious
New member
A deep enough RDSB will keep those nitrates at ZEEEERRRRRO no matter how much you feed.
no water changes, no nitrate?
- Thread starter joshPensacola
- Start date
Reefin' Dude
New member
no.
it all depends on the organisms in the substrate. some are helpful for helping the slow migration of phosphates down through the substrate others actually feed on the organisms that are helping the slow migration. using just the critters that come in with LR or normal LS from somewhere else is fine. i would not however use sand sifting stars or sand sifting gobies for this purpose as they only feed on the very top can deplete this layer of the more beneficial organisms moving the phosphates lower. sure, if nitrates were really something to worry about, but in reality they are not and the risk of running a device that will create H2S as a final product if not tweeked right, or worse if flow were to stop in the device, say power outage, then the denitrator will flow H2S into the system, or at the very least very high levels of CO2.
at least until the substrate gets clogged from all of the detritus being formed from all of the feeding. calcium carbonate will absorb phosphates whether you like it or not. bacteria are going to use those phosphates for the same biological function they do for converting nitrates to N2 gas, so you can see where this is going to go.
bacteria die, they form detritus. this detritus is already in the substrate, where does it go? this is part of that slow migration of phosphates. the more you feed, the more phosphates, the more detritus, the more detritus, the sooner the substrate will clog. a filter can only last so long before needing to be cleaned. in the case of DSB's it can be years, but at some point it is going to need to be replaced or cleaned. in the case of RDSB's, not a big deal. remove it, chuck it, replace it, a new load of phosphates binding sites for another X amount of time. G~
Dexters Reef
New member
Not trying to argue, but I really dont think I'm overfeeding. By your ratio of 2 cubes daily per 500 gallons, that would mean as a general rule people should feed 2/25th of a cube daily, per 20 gallons. That really sounds on the LOW side for me.
I feel my ratio of 2 cubes daily per 80 gallons is fine, that equates to .5 cubes daily per 20 gallons which is is a standard many people use. Many of my fish wouldnt be able to even get a bite if I fed such a small amount at at time (1/25 cube twice daily)! I have 8 fish, and the 4 chromis are very fast eaters...like a shark pack. I need to use a whole cube just to make sure the other fish get some.
I also said my cycle finished over 6 months ago, it has been running for 10 months so its really like a 9 month old tank. Not a huge difference, still new, but a little older than I accidentally implied. Much of the rock came from my 46g reef, that is almost 7 years old, with a DSB that never crashed. When everything was in that tank, I was feding 1 cube in the morning plus flakes at night every day. I only have about 10 lbs left of rock in that tank, because I moved all of it to my newer tank, and it didnt bring any phosphate issues with it.
I'm not going to change my feedings, but will modify my maintenance. The point of my third post was to ask for help, to prevent the "ticking time bomb" I'm being warned about.
It seems that the biggest issue is going to be my dsb about 4 years from now. "Cleaning" the sandbed is what people suggest above, and Reefin Dude has given some good advice in his reply.
I think I will increase to weekly siphoning of my top 1" and aim for a deep siphoning every 3 months. This way I can eliminate detritus before it really builds up, and removing a small amount of build up every 3 months will impact my system less than removing a larger amount on a less frequent basis. My fear is that I will remove the beneficial stuff every 3 months, and start mini cycles again.
To get back on topic, I do think with a DSB you can reduce (but not eliminate) water changes, but the key is maintaining the DSB to prevent problems down the line as we kinda segued into.
Reefin Dude, do you think a siphoning of the top 1" weekly, and a deep siphoning of all accessible sand every 3 months is too often? Any one else have any reccomendations?
BeanAnimal
Premium Member
The volume really has little to do with the "needed amount of food", but was presented to put in perspective the typical fish load of a systme that size. Clearly (or maybe not) the larger the volume of the system, the more capacity it has to handle overfeeding, both from a sequestration perspective and a biological filtration perspective.
Fish will in effect eat as much as you feed them, but in reality require very little actual imported food to survive (depending on species).
Cubed food can help to feed some corals as well, but containes a tremendous amount of phosphate, much of which enters the water column directly before it is "eaten".
Water changes, skimming, ATS... all tools. Whatever you do, you need to be using enough of them to prevent the phosphate from being sequestered IN the system, as it will be liberated one day and bad things will happen.
Reefin' Dude
New member
the big issue is where can the left overs hide, and the total amount of organisms necessary to sequester them, if a more aggressive removal method is not employed.
the more places the leftovers can hide the more organisms necessary to sequester the nutrients in order for the nutrients to be not seen by the system, meaning algae showing its ugly head. there is nothing wrong with collected as much as possible in a single area where low oxygenation slows the process of decomposition to a level that allows a weekly removal to be all that is needed for the really big stuff. the smaller stuff can be removed eventually, or settled out in the same place as the larger stuff, by the skimmer.
DR- there are a lot of factors that go into extending the life of a DSB. any amount of siphoning is fantastic. whether it is just the top bit every week, digging deeper with a siphon, or even just poking holes in the substrate down to the bottom to get more carbon influx for even a few seconds can do wonders for prolonging and helping the slow migration of phosphates down through the substrate. this all goes into what fits your ideal of maintenance. this all falls into the annoying "multiple ways to skin a cat". i hate that saying BTW. in our case the skinned cat is a nutrient export model that equals the import model for the given trophic level wishing to be emulated. unless this balance is made the cat is not skinned, we may be flopping around with a bunch of various tools, but the cat is still dancing with its hat on and having a good ol time. even if we are saying we are actively skinning it.
G~
the more places the leftovers can hide the more organisms necessary to sequester the nutrients in order for the nutrients to be not seen by the system, meaning algae showing its ugly head. there is nothing wrong with collected as much as possible in a single area where low oxygenation slows the process of decomposition to a level that allows a weekly removal to be all that is needed for the really big stuff. the smaller stuff can be removed eventually, or settled out in the same place as the larger stuff, by the skimmer.
DR- there are a lot of factors that go into extending the life of a DSB. any amount of siphoning is fantastic. whether it is just the top bit every week, digging deeper with a siphon, or even just poking holes in the substrate down to the bottom to get more carbon influx for even a few seconds can do wonders for prolonging and helping the slow migration of phosphates down through the substrate. this all goes into what fits your ideal of maintenance. this all falls into the annoying "multiple ways to skin a cat". i hate that saying BTW. in our case the skinned cat is a nutrient export model that equals the import model for the given trophic level wishing to be emulated. unless this balance is made the cat is not skinned, we may be flopping around with a bunch of various tools, but the cat is still dancing with its hat on and having a good ol time. even if we are saying we are actively skinning it.
G~
SantaMonica
Well-known member
Best description I've read in a long time
We had to do water changes for a good long time untill our system was fully established. All you are really doing is removing a percentage then adding water back to dilute the rest.
We found that as the system aged everything came into almost a balance and our " water changes" became more about just topping the system off. Even our salinity stayed fairly stable that way. I think I has to do with establishing a fairly complete eco system then doing things to maintain that. Our system wound up being hundreds of gallons with many types of ecosystems tied together over time. I guess we had a refugium although I dont even remember knowing what one was back then. To us it was just a super low flow hex as a plant tank with a pair of sea horses in it. We really didnt know it was helping our reef. We also had major water volume. If I had to guess it was 400-500 gallons. The reef was a 110 but loaded with rock and a deep sand bed. I dont remember what brand skimmer we had but the darn thing was all or 5ft tall
Im not the chemistry type nor do I claim to be a "pro" I just think people focus more on pinpoint details putting bandaid after bandaid on them and dont take the time to stand back and look at the system as a whole. Sadly I also feel many over load there system by confusing tank volume with water volume. Yeah the 200 gallon tank with the 60 gallon sump looks nice and big. But take the 200lbs of rock out, the 3inches of sand and everything else and see how much water you actually have left sitting in the bottom of your tank. That is the important part IMHO
We found that as the system aged everything came into almost a balance and our " water changes" became more about just topping the system off. Even our salinity stayed fairly stable that way. I think I has to do with establishing a fairly complete eco system then doing things to maintain that. Our system wound up being hundreds of gallons with many types of ecosystems tied together over time. I guess we had a refugium although I dont even remember knowing what one was back then. To us it was just a super low flow hex as a plant tank with a pair of sea horses in it. We really didnt know it was helping our reef. We also had major water volume. If I had to guess it was 400-500 gallons. The reef was a 110 but loaded with rock and a deep sand bed. I dont remember what brand skimmer we had but the darn thing was all or 5ft tall
Im not the chemistry type nor do I claim to be a "pro" I just think people focus more on pinpoint details putting bandaid after bandaid on them and dont take the time to stand back and look at the system as a whole. Sadly I also feel many over load there system by confusing tank volume with water volume. Yeah the 200 gallon tank with the 60 gallon sump looks nice and big. But take the 200lbs of rock out, the 3inches of sand and everything else and see how much water you actually have left sitting in the bottom of your tank. That is the important part IMHO
In 25 years of setting up reef tanks i know one thing and only
1 thing that will keep nitrates under 1ppm and that a SUGAR sized sand
dsb.
Just use very little rock and have a nice flow around a 4/6 inch bed
of fine sand and have a very aggressive skimmer.
Put a dsb and a etts1000 on any 150 or bigger tank and its money.
1 thing that will keep nitrates under 1ppm and that a SUGAR sized sand
dsb.
Just use very little rock and have a nice flow around a 4/6 inch bed
of fine sand and have a very aggressive skimmer.
Put a dsb and a etts1000 on any 150 or bigger tank and its money.
Gsxr600
New member
IME, nitrate problems= too many fish, too much feeding, or you're not using RO water.
phosphates= poor choice of fish food, not using ROwater.
water changes aren't to get rid of nitrates or phosphates unless you already have an elevated level of them to begin with. water changes are mainly to replace/ refresh trace elements.
phosphates= poor choice of fish food, not using ROwater.
water changes aren't to get rid of nitrates or phosphates unless you already have an elevated level of them to begin with. water changes are mainly to replace/ refresh trace elements.
SantaMonica
Well-known member
Well of course, enough export will take care of any amount of N or P in the system.
BeanAnimal
Premium Member
Water changes can certainly help to reduce ("export") both N and P, however like any "tool" they have their place and limitations.
Where changes may not be a sole effective means of export in systems where large amounts of Phosphate is sequestered in rock, substrate (a DSB in poor health), etc.
The irony is that the poor DSB health and/or high levels of sequestered phosphate are often the result of the neglect to do water changes and/or incorporate effective means of export.
Likewise, a system with excess nutrients (again due to poor husbandry, lack of proper export and/or water changes) can have significant nitrate problem that simple water changes can not overcome. Like the phosphate problem, the water changes would have helped to prevent the problem in the first place but are not efficient after the fact.
There is no "single" filtration method or device that is a magic bullet. Each of our systems is vastly different. We have different biological loads, balances of micro and macro arganisms, feeding habbits, lighting spectra and cycles, system volume and flow rates and patterns, and environmental parameters. In the end, one has to find a balance of "tools" to maintain the long term health of the system, be it BB, DSB, SSB, or anything in between. Some of the "tools" are water changes, skimmers, mechanical filtration, algal export (ATS, Refugium, etc), chemical filtration (phosphate, and other binders, lanthanumum chloride, etc), UV units, and various other devices and technologies.
Can you get away with no water changes? Sure, if there are other means in place to maintain the nutrient levels and biological processes. What works on "tank A" may not work on "tank B" due to the differences in environment.
Where changes may not be a sole effective means of export in systems where large amounts of Phosphate is sequestered in rock, substrate (a DSB in poor health), etc.
The irony is that the poor DSB health and/or high levels of sequestered phosphate are often the result of the neglect to do water changes and/or incorporate effective means of export.
Likewise, a system with excess nutrients (again due to poor husbandry, lack of proper export and/or water changes) can have significant nitrate problem that simple water changes can not overcome. Like the phosphate problem, the water changes would have helped to prevent the problem in the first place but are not efficient after the fact.
There is no "single" filtration method or device that is a magic bullet. Each of our systems is vastly different. We have different biological loads, balances of micro and macro arganisms, feeding habbits, lighting spectra and cycles, system volume and flow rates and patterns, and environmental parameters. In the end, one has to find a balance of "tools" to maintain the long term health of the system, be it BB, DSB, SSB, or anything in between. Some of the "tools" are water changes, skimmers, mechanical filtration, algal export (ATS, Refugium, etc), chemical filtration (phosphate, and other binders, lanthanumum chloride, etc), UV units, and various other devices and technologies.
Can you get away with no water changes? Sure, if there are other means in place to maintain the nutrient levels and biological processes. What works on "tank A" may not work on "tank B" due to the differences in environment.
Paul B
Premium Member
As Reefin Dude mentioned I run a reverse UG filter and it has been running my reef for 42 years now, but I do have to stir it up where I can reach with a power filter a couple of times a year and about every ten years I remove some rocks and do a better job. But I don't have to remove the plates. So I did that about 3 times in all those years but the tank is very healthy and has never crashed. I grow LPS and SPS with no problems and many of the fish are spawning including the 19 year old fireclowns, so a RUGF can work but I am probably the only one who uses one.
Reefin' Dude,
According to your theory, If you don't change your substrate over time, your system will crash over time no matter what. Let's say if you don't do water changes it will in 4 years, if you do water changes in 8 years. In the chart, even though water changes removes more organic phosphates, it's not removing all the organic phosphates so your system will eventually crash. I don't really aggree.
Also I don't aggree with the chart which shows water changes can remove more organic detrius than a good skimmer on tank with good water flow. If there's very good flow and organic phosphates are suspended in the water column, then skimmer can effectively remove the deitrus as it can work 24/7.
When you do water changes, water flow stops and organic phosphates(deitrus) sinks in to your substrate and no matter how much you try to siphon, you won't get much deitrus in 10 mins of siphoning . Especially, if you have deep sand bed, I would not recommnend siphoning it at all.
I think key is to keep the detirus suspended in water column with very good water flow so all your export methods can work effectively to remove it from the water columns.
If it sinks to the substrate I don't think water changes has any advantage over skimmer, algea or etc
According to your theory, If you don't change your substrate over time, your system will crash over time no matter what. Let's say if you don't do water changes it will in 4 years, if you do water changes in 8 years. In the chart, even though water changes removes more organic phosphates, it's not removing all the organic phosphates so your system will eventually crash. I don't really aggree.
Also I don't aggree with the chart which shows water changes can remove more organic detrius than a good skimmer on tank with good water flow. If there's very good flow and organic phosphates are suspended in the water column, then skimmer can effectively remove the deitrus as it can work 24/7.
When you do water changes, water flow stops and organic phosphates(deitrus) sinks in to your substrate and no matter how much you try to siphon, you won't get much deitrus in 10 mins of siphoning . Especially, if you have deep sand bed, I would not recommnend siphoning it at all.
I think key is to keep the detirus suspended in water column with very good water flow so all your export methods can work effectively to remove it from the water columns.
If it sinks to the substrate I don't think water changes has any advantage over skimmer, algea or etc
best comment I've read in this thread
Reefin' Dude
New member
look at the chart again. it depends on which water change method you are using. if you just changing water, then you are just removing the stuff in yellow, the upper right graphic. you are correct, this is a very inefficient way to remove nutrients.
if you believe that detrital removal is the reason for doing water changes, then you use the green graphic in the lower left. this removes the source of P from the system before it can liberated. if this is done aggressively enough, then the other methods become far less effective also. the object is to actually go after the source, not the product.
you are at best going to be able to keep the water borne detritus in suspension. you are not however going to get to the substrate borne detritus. it is this detritus that is the biggest problem. all of those little organisms in the substrate poo and die. the bacteria are also doing their job within the substrate. unfortunately their job produces more detritus that stays in the substrate.
one must think about what is the substrate really doing for them. if you design the system with detrital export as a priority. in my system 10 minutes was enough time to remove essentially all detritus from my system. if you give it no place to hide, then how can it become a problem later?
G~
SantaMonica
Well-known member
Keep in mind that organic phosphates are food particles, like shrimp, pellets, flakes, bbs, silversides, and even peanut butter.
Your corals are hungry...
110galreef
New member
Just my input and process:
-250gallon SPS dominate DT Shallow Sand Bed and about 150# dry rock,
-100g grow out ~15# dry rock and BB, 65g sump.
-SRO XP 3000e Skimmer rox.08 Carbon. 2 part dosing with BRS.
-NO fuge, NO GFO, NO ATS, NO pellets, no nothing extra.
-I skim avg to a tad wet. I am pulling about 4 cups of skimmate every 2-3 days or about 1g every 10days
Tank is 2.5yrs old now. SPS colors excellent and growing good. No algae issues at all. Very small clean up crew.
4 FAT tangs, trigger and about 16 other medium sized fish like small angels, wrasses,clowns, chromis etc....
I feed the good frozen food mostly. Like Rods or Larrys food. I will feed flake or pellet when pressed for time. I occasionally(once every week) will feed the tank stuff like reef roids, corals frenzy, reef chilli,
I did about 10% wc every 2-3 weeks for first yr. Last 1.5 yrs I have been doing like ~ 25g (8%)WC every 3-4 mos. I transition from the every to weeks to where I am at now over a period of like 4-6 mos to ensure no issues. I willprobably stick with te 4 mos ~ 8-10% WC just because I like to do a little something and a 200g box of Kent for $45 will last me a yr!! Cheap WC for ~ 325 net gallons
Nitrates & nitrites: 0
PO4 .01 or less usually
CAL:440
ALK: 8.5
SG: 35ppt
I recently ~4-5weeks started dosing 25ml of vinegar a day just to experimnet and see if SPS reacted positively. Only things i noticed is my PO tested at 0 most all the time now, and even increased filter foods a little more to compensate. Also skimmer skimmed a little better.
I will stop the vinegar probably or just keep adding like 15ml to help the skimmer export??
-250gallon SPS dominate DT Shallow Sand Bed and about 150# dry rock,
-100g grow out ~15# dry rock and BB, 65g sump.
-SRO XP 3000e Skimmer rox.08 Carbon. 2 part dosing with BRS.
-NO fuge, NO GFO, NO ATS, NO pellets, no nothing extra.
-I skim avg to a tad wet. I am pulling about 4 cups of skimmate every 2-3 days or about 1g every 10days
Tank is 2.5yrs old now. SPS colors excellent and growing good. No algae issues at all. Very small clean up crew.
4 FAT tangs, trigger and about 16 other medium sized fish like small angels, wrasses,clowns, chromis etc....
I feed the good frozen food mostly. Like Rods or Larrys food. I will feed flake or pellet when pressed for time. I occasionally(once every week) will feed the tank stuff like reef roids, corals frenzy, reef chilli,
I did about 10% wc every 2-3 weeks for first yr. Last 1.5 yrs I have been doing like ~ 25g (8%)WC every 3-4 mos. I transition from the every to weeks to where I am at now over a period of like 4-6 mos to ensure no issues. I willprobably stick with te 4 mos ~ 8-10% WC just because I like to do a little something and a 200g box of Kent for $45 will last me a yr!! Cheap WC for ~ 325 net gallons
Nitrates & nitrites: 0
PO4 .01 or less usually
CAL:440
ALK: 8.5
SG: 35ppt
I recently ~4-5weeks started dosing 25ml of vinegar a day just to experimnet and see if SPS reacted positively. Only things i noticed is my PO tested at 0 most all the time now, and even increased filter foods a little more to compensate. Also skimmer skimmed a little better.
I will stop the vinegar probably or just keep adding like 15ml to help the skimmer export??
Last edited:
inclined to agree....10 % WC once a month and nitrates at 0 since the cycle 2 years ago...but have 5 inch DSB
BeanAnimal
Premium Member
Your only means of export is a minimally producing skimmer and almost non existent water changes. Everything looks great but where does all the phosphate go? I would submit that, without question, your DSB will crash in the not so distant future, taking the health of your tank with it....
You will get further down the road than the guy with no DSB, or the guy with the same bioload stuffed into a 100 gallon tank, but the DSB is not magic and is not a limitless phosphate sink.
Look at it this way:
You can buld a bigger litter box and layer the litter deeper, but if you don't scoop it often enough, the cat poop will eventually start to stink...
