No dosing No WC. How long can it last?

[29bonsaireef]

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?

IMO, even if I knew the systems daily rate of consumption. It would still be hard to estimate an amount of time before things stopped growing, because I have no idea what the lowest levels that could sustain growth in the tank are. I'm sure at whatever level dkh is at currently I would've expected growth to have stopped.

 

[Bayareareefer18]

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.

+1
At this point I would be more concerned with stress to the coral than potential for growth rate.

IMHO if it were my tank

 

[Lasse]

Growth of hard corals have two major pathways, growth of the soft tissue and growth of the hard calcium carbonate "skeleton". Both pathways demand energy input and building bricks from the water. This energy input will be present in two ways – by coral feeding and by photosynthesis. The energy input from the photosynthesis is normally the most important. The energy from this will together with nutrients in the water form the soft tissues and together with Ca and CO3/HCO3 (what we normally call alkalinity) it will form the hard CaCO3 that support the soft tissues of the stony corals. Because – normally – seawater have an “oversaturation” of calcium and in some way carbonates – the forming of CaCO3 normally needs lesser energy demand for growth compared with lower content of Ca and CO3/HCO3. Shortly – if your concentration of Ca and CO3/HCO3 get lower, the energy demand for forming CaCO3 will be higher and when all energy reserves is used – the forming (growth) of CaCO3 will get slower. If these changes happen slowly – I do think that there will be a point of concentrations, there the growth of CaCO3 will stop but that´s not connected with the surviving of the soft tissues that is more is in demand of nutrient and trace elements. The input of external food to your fish will probably give your corals soft tissue what they need for surviving.

However, if the alkalinity drops to much – you will see a pH drop that can affect all calcium carbonate structures in your aquarium but also stabilize the situation.

IMO if this happens slowly – as in your case – I think everything will stabilize in one or another concentration of Ca and CO3/HCO3 with very low growth of the corals – but I think they survive.

But when you will start to make your aquarium optimal again – do it slowly, very slowly.


Sincerely Lasse

 

[Jon Fishman]

The toothpaste is out of the tube already, but if you know you're going out of town with any (a day or two) notice, then the big water change beforehand would be ideal. I doubt your tank would die off and not rebound after in under 5 months or so.

 

[29bonsaireef]

Growth of hard corals have two major pathways, growth of the soft tissue and growth of the hard calcium carbonate "skeleton". Both pathways demand energy input and building bricks from the water. This energy input will be present in two ways – by coral feeding and by photosynthesis. The energy input from the photosynthesis is normally the most important. The energy from this will together with nutrients in the water form the soft tissues and together with Ca and CO3/HCO3 (what we normally call alkalinity) it will form the hard CaCO3 that support the soft tissues of the stony corals. Because – normally – seawater have an “oversaturation” of calcium and in some way carbonates – the forming of CaCO3 normally needs lesser energy demand for growth compared with lower content of Ca and CO3/HCO3. Shortly – if your concentration of Ca and CO3/HCO3 get lower, the energy demand for forming CaCO3 will be higher and when all energy reserves is used – the forming (growth) of CaCO3 will get slower. If these changes happen slowly – I do think that there will be a point of concentrations, there the growth of CaCO3 will stop but that´s not connected with the surviving of the soft tissues that is more is in demand of nutrient and trace elements. The input of external food to your fish will probably give your corals soft tissue what they need for surviving.

However, if the alkalinity drops to much – you will see a pH drop that can affect all calcium carbonate structures in your aquarium but also stabilize the situation.

IMO if this happens slowly – as in your case – I think everything will stabilize in one or another concentration of Ca and CO3/HCO3 with very low growth of the corals – but I think they survive.

But when you will start to make your aquarium optimal again – do it slowly, very slowly.


Sincerely Lasse

I appreciate the info here. This is along the lines of the conclusion I came to myself. Without the scientific knowledge in my case, and relying on my past experiences. I assumed growth would stop somewhere, but was thinking (hoping) the living tissue part of the corals would survive for a decent amount of time from the energy they receive from the light, and fish. Im planning to get some fresh sea water into the tank as soon as I'm able to, before growth has stopped completely.

The toothpaste is out of the tube already, but if you know you're going out of town with any (a day or two) notice, then the big water change beforehand would be ideal. I doubt your tank would die off and not rebound after in under 5 months or so.

I did manage to change out 100 gallons before I left, and it must have been enough to replenish the system. I don't think I will let it go to 5 months, but it may be 4 before I'm able to change some water.

 

[29bonsaireef]

Decided not to let it go any longer.. So, I had my brother do a 40gal WC for me. He tested the dKh before hand just to know out of curiosity, 5.3 is where it was at. Close to the number I was thinking. For the most part everything still looks okay. Better than I would've ever expected it to after a 3 month roll of the dice with no maintenance. NO deaths or STN reported. Pics of some of the acros right before the WC. Most SPS still had PE, and some had color. Only thing that really irked me out was that nasty looking cyano.

 

[laverda]

My corals look much worse than yours when my alk drops to 7. Each tank is different.

 

[Lasse]

If you have cyano bacteria - it could indicate a lack of NO3 or/and PO4. That's for me a greater concern of surviving than a slow drop in alk

Sincerely Lasse

 

[roberthu526]

IMO, even if I knew the systems daily rate of consumption. It would still be hard to estimate an amount of time before things stopped growing, because I have no idea what the lowest levels that could sustain growth in the tank are. I'm sure at whatever level dkh is at currently I would've expected growth to have stopped.

So you are trying to grow corals in the worst condition before they die? I am confused about why you want to find out the lowest level. Most of us here look for the best condition to keep the corals happy and grow fast.

 

[SeaDweller]

So you are trying to grow corals in the worst condition before they die? I am confused about why you want to find out the lowest level. Most of us here look for the best condition to keep the corals happy and grow fast.

I think he’s trying to make the best of a bad/unknown situation. His hand was sort of forced into the predicament he’s in.

 

[29bonsaireef]

My corals look much worse than yours when my alk drops to 7. Each tank is different.

Yes, I'd agree. I think in my case, or any similar, it comes down to tank stock. Had my SPS been more colony size instead of frags, I don't think they would have made it this long.

If you have cyano bacteria - it could indicate a lack of NO3 or/and PO4. That's for me a greater concern of surviving than a slow drop in alk

Sincerely Lasse

NO3/PO4 are low for sure. Both undetectable last time I checked. The system previously was FOWLR and had some bad HA. I'd rather deal with some cyano then HA.

So you are trying to grow corals in the worst condition before they die? I am confused about why you want to find out the lowest level. Most of us here look for the best condition to keep the corals happy and grow fast.

I'm just not able to keep up with my system at this point in time. You could say it was for experimental purposes, seeing that I did learn something new. I would not let them get to the point of death. If something RTNs, not much I can do. I get pics every other week or so to make sure corals are still living.

 

[Turtlesteve]

Quick thought - I agree with Lasse's comment. Low N/P is a bigger concern.

If the Acro's are not growing quickly (and shouldn't be at 5-5.5 alk) then very pale tips and loss of coloration both indicate low nutrient levels as you have confirmed. I'd try to get nutrient levels up and throw in some turbo snails to eat any resurgent HA.

 

[Chip]

Until the colonies get to big and suck up all your nutrients and elements. My tank lasted a year now I have to supplement. Nickel, potassium, strontium zinc, iodine, and yes I'm dosing nitrates. But this is a SPS dominant tank.

 

[29bonsaireef]

Quick thought - I agree with Lasse's comment. Low N/P is a bigger concern.

If the Acro's are not growing quickly (and shouldn't be at 5-5.5 alk) then very pale tips and loss of coloration both indicate low nutrient levels as you have confirmed. I'd try to get nutrient levels up and throw in some turbo snails to eat any resurgent HA.

Growth is within an OKAY range, imo. It would be a lot better if I was taking care, and performing frequent WC.

I tend to enjoy the pastel colors of low N&P tanks more then the deeper color you get with higher N&P levels. I think the lack of elements from no WC's probably has some effect on coloration, maybe more than where my N&P levels are at. I usually feed 3-4x a day. Currently the tank is fed 1-2x a day, so there is definitely a lack of available food source from the fish, but my export system is not strong enough to ever completely bottom out N&P.