No dosing No WC. How long can it last?

[29bonsaireef]

Work has me away from home currently so I am not able to keep up with my tank the way I would like. I have someone who feeds the fish daily, and tops off RO when needed. Besides this there is zero tank maintenance. Last WC was early March, and zero dosing since. It shocks me, not that the corals are still alive, but most growing at an okay pace. I know at some point the supply of Cal/Alk has to run too low to keep them growing, but my question is, how long until that happens? Anyone ever let a tank run itself without dosing, and were you able to keep SPS growing for a certain length of time? Most SPS are frags, some mini colonies, and some bigger colonies of hammers, and torches

Tank is a 150, with a 30gal sump/fuge and a skimmer. I don't know any numbers besides no3/p04, because I bottomed them out to avoid algae while I'm away. Last WC was about 100 gallons of NSW 3 months ago.

 

[SeaDweller]

I just realized you’re not at home and have been away. You got a buddy who can test for you and do a WC for you?

 

[29bonsaireef]

I just realized you’re not at home and have been away. You got a buddy who can test for you and do a WC for you?

I don't know anyone who could do a WC with NSW. I have a guy that does WC with salt mix, but the dkh runs high around 9, which worries me. There's no real issue for now. I'm kind of just curios if anyone has ever tried to let their tank run itself, and if so, for how long? and what happened? I'm just surprised at 3months with nothing being added things are still growing.

 

[Pete_the_Puma]

No one except your tank can answer that question. It really depends on how good your system is at keeping Nitrate and Phosphate low and how much Akl/Cal your system consumes. Your alkalinity and calcium will drift down but if that happens slowly it should not kill the corals, just slow growth IMO. It might be worth having whoever is filling up the RO water for the top off add a little KAlkwasser in there for both CAL and Alk, although personally I would not do that without testing...

 

[29bonsaireef]

You're right, and I have thought about adding Kalk, but the RO top off is done manually out of a jug every day or so. I don't want any numbers bouncing around from the random addition of kalk.

Just wondering if anyone has experimented with letting an established tank "run its course" and how long they were able to get away before seeing negative effects?

 

[TaylorJames]

I agree with @Pete_the_Puma. There is no way for any of us to know. It entirely relies on the nutrient consumption for your tank. One tank could last 6 months and another could last 1 week. My tank is covered in coralline and a bunch of sps frags and goes through about .1-.2 dkh /day. I keep the tank at 8.2 dkh so I would imagine after a couple of weeks my tank would be looking pretty sad.

 

[SeaDweller]

It seems odd to me your alk doesn’t dip down after 3 months?

 

[29bonsaireef]

I'm aware, and asking as more of general question to hear if others have gotten busy/stopped taking care of a system, and how long it lasted.

It's odd to me as well. I'm positive it has to be going down with the growth of hard corals/coralline. I would guess it's getting real low, but the the slow steady dip must not bother the corals too much. I'd assume at some point, maybe soon, growth will slow significantly or stop without WC or additives.

 

[Turtlesteve]

You don't specify what SPS. Based on past experience, maybe 4-5 months with no tank maintenance or water changes - IF you top off evaporation, dose some Ca/Alk, and nothing else goes wrong. Automatic topoff with kalk is really cheap to set up.

If you roughly know the tank's alkalinity consumption, you can blindly dose balanced Ca/Alk at something like 1/2 to 2/3 the ideal rate without testing Ca/Alk. Alk will stabilize somewhere (near 5-6 dKh in my case) and coral growth will slow down overall.

Steve

 

[29bonsaireef]

You don't specify what SPS. Based on past experience, maybe 4-5 months with no tank maintenance or water changes - IF you top off evaporation, dose some Ca/Alk, and nothing else goes wrong. Automatic topoff with kalk is really cheap to set up.

If you roughly know the tank's alkalinity consumption, you can blindly dose balanced Ca/Alk at something like 1/2 to 2/3 the ideal rate without testing Ca/Alk. Alk will stabilize somewhere (near 5-6 dKh in my case) and coral growth will slow down overall.

Steve

I have a bunch of miscellaneous SPS, mostly Acropora, some Montis and BN too.

So in your experience, coral growth slowed enough at around 5-6 dkh to stop consuming? That's kind of what I was curious about, just didn't know at what levels growth might slow enough to where the corals stopped consuming dkh.

I'm very familiar with Kalkwasser. I will set up my doser to drip kalk next time I work on the tank. I knew the last time I did a WC the coral to water volume ratio was not enough, at least imo, to worry about dosing quite yet. However, I was not expecting things to seemingly be so happy 3 months later

 

[jda]

If I go 3-4 months without a water change, I can get a growth spurt when I do change water. Nothing was suffering, just not thriving as much.

Nuance matters here - I am not a no-water-change guy, so I do not supplement traces and stuff. ...so this is an issue for me. Most of the people who do not change water for long periods of time spend more effort than I do to make sure that stuff is OK. I do run CaRx, so I do get most of the hard traces.

If you ever need this, you can lower fresh salt mix dKh with muratic acid... gallons * dKh drop * .123 is the number of mls of muratic acid to use. You need to aerate it for a extra day or two until the pH comes back up.

 

[RCS82]

Kalk and an ATO could go a long ways for you but I dont think I would stock a tank with sps and then wonder while I'm away if I'll come home to anything alive. I would put some systems in place before I leave. If you've been monitoring your tank and all is well then that's great and hopefully it stays great.
Cheers

 

[Turtlesteve]

I have a bunch of miscellaneous SPS, mostly Acropora, some Montis and BN too.

So in your experience, coral growth slowed enough at around 5-6 dkh to stop consuming? That's kind of what I was curious about, just didn't know at what levels growth might slow enough to where the corals stopped consuming dkh.

I'm very familiar with Kalkwasser. I will set up my doser to drip kalk next time I work on the tank. I knew the last time I did a WC the coral to water volume ratio was not enough, at least imo, to worry about dosing quite yet. However, I was not expecting things to seemingly be so happy 3 months later

They didn't stop growing completely, just slowed enough to balance dosing and consumption. I suspect it will go below 5 if you don't dose at all. It also varies for different corals. In my case, monti caps and tridacna clams kept growing at the expense of everything else.

Steve

 

[29bonsaireef]

I'm an advocate for frequent WC, always have been on the weekly/bi-weekly program. I do not enjoy testing, dosing, etc.. and rarely ever do because I rely on those frequent WC. My system was not prepared for running extended periods of time with no WC.

Though I was never super worried about major issues. I did not expect corals, especially the acros to still be growing this far in. Growth is not amazing, but it's not the worst either. I will have to test dkh to see how low it got before the next WC.

I've heard about the muriatic acid before. Fortunately, I'm able to collect NSW for WC, and prefer this over the mixed salts.

 

[Backreefing]

I let an aquarium go for LONG time 10 years + - 1 or 2 and it wasn’t that bad almost all the stonie corals died except 1 and mushrooms took over . The coraline algae took a big hit . And colonial hybrids were everywhere. There was no fish either.
Notice my name ( backreefing)

 

[Backreefing]

This past year I got back in starting with a new light , then some cleanup water changes. And jumped right in with a cheap no name acropora for $20 and then I joined R2R

 

[29bonsaireef]

I let an aquarium go for LONG time 10 years + - 1 or 2 and it wasn’t that bad almost all the stonie corals died except 1 and mushrooms took over . The coraline algae took a big hit . And colonial hybrids were everywhere. There was no fish either.
Notice my name ( backreefing)

That's pretty wild. I suppose I don't really see any reason why a well established tank couldn't keep softies growing forever.. as long as salinity was maintained, and good lighting.

 

[roberthu526]

Without testing no one can tell you how long it will last.

 

[Bayareareefer18]

I would think the only way to answer your question is test the water to find out what your daily consumption is. That would give you an idea of how long you could go but isn't SPS all about stability?

If you reply solely on WC and travel often have you ever considered an auto water change system to keep things stable?

 

[laverda]

I would think your pushing it if growth has slowed already. Testing your ALK will answer the question. I am sure it will be low, but how low? Don’t increase it to quickly or you will have problems.