Thoughts on massive water change?

[Anonymous]

What are your thoughts on a massive water change?

I have a 29G Biocube with ~30 lbs of LR. The cyano is really bad now and covers everything after a few days. I have been doing 5G water changes every other week and for a while was doing them weekly with no luck.

I am thinking of changing 15G on the next water change. This will basically be ~60-70% of the water in the tank.

I use RO.DI - 0 TDS
IO Salt
Feed Rods food the size of my pinky nail every other day The tank has a Sapphire skimmer as well.

 

[Len]

I've never had problems with big water changes when using the same salt mix and mixing it to the same salinity and temp. However, there's a school of thought (championed by Julian Sprung IIRC) that water changes are a bad idea with cyano and dino blooms because they add trace elements that fuel their growth. I'm not sure I totally agree. However, you might want to try changing/adding GAC and GFO first. These helped get my nutrients under control. I had bad dinos and some cyano last month, but it's mostly gone away now that I changed the GAC and added GFO. Vodka dosing could also work, but just be careful with it (less is better than more when dosing Vodka).

 

[Anonymous]

What are your thoughts on a massive water change?

well known. :lol:

I have a 29G Biocube with ~30 lbs of LR. The cyano is really bad now and covers everything after a few days. I have been doing 5G water changes every other week and for a while was doing them weekly with no luck.

I am thinking of changing 15G on the next water change. This will basically be ~60-70% of the water in the tank.

I use RO.DI - 0 TDS
IO Salt
Feed Rods food the size of my pinky nail every other day The tank has a Sapphire skimmer as well.

I would kill the lights untill the cyano dies off then resume with 1/2 duration lighting and adjust until corals, coraline, and other desirables keep the cyano away.


my .02

 

[Anonymous]

Out of curiosity how do you do your water changes? Do you simply siphon the water out? If so you might want to actively siphon the cyano out.

Maybe add a bit more flow to the tank to prevent the cyano from covering everything, however this doesn't address the reason why it's there in the first place. Could be nutrients stuck in the rock or something. Sometimes its simply a matter of being quite diligent with siphoning out as much as possible while your doing the water changes and eventually you'll get on top of it. While I don't think there's anything wrong with a large water change I don't see it as making a dent in your cyano.

 

[Anonymous]

Out of curiosity how do you do your water changes? Do you simply siphon the water out? If so you might want to actively siphon the cyano out.

Maybe add a bit more flow to the tank to prevent the cyano from covering everything, however this doesn't address the reason why it's there in the first place. Could be nutrients stuck in the rock or something. Sometimes its simply a matter of being quite diligent with siphoning out as much as possible while your doing the water changes and eventually you'll get on top of it. While I don't think there's anything wrong with a large water change I don't see it as making a dent in your cyano.

I siphon the sump area and the rocks and as much cyano as I can get with the 5G change.

 

[Anonymous]

I've never had problems with big water changes when using the same salt mix and mixing it to the same salinity and temp. However, there's a school of thought (championed by Julian Sprung IIRC) that water changes are a bad idea with cyano and dino blooms because they add trace elements that fuel their growth. I'm not sure I totally agree. However, you might want to try changing/adding GAC and GFO first. These helped get my nutrients under control. I had bad dinos and some cyano last month, but it's mostly gone away now that I changed the GAC and added GFO. Vodka dosing could also work, but just be careful with it (less is better than more when dosing Vodka).

GAC and GFO need a food flow of water through them to work? There is no where good in the tank to get good flow through them.

 

[Anonymous]

What are your thoughts on a massive water change?

well known. :lol:

I have a 29G Biocube with ~30 lbs of LR. The cyano is really bad now and covers everything after a few days. I have been doing 5G water changes every other week and for a while was doing them weekly with no luck.

I am thinking of changing 15G on the next water change. This will basically be ~60-70% of the water in the tank.

I use RO.DI - 0 TDS
IO Salt
Feed Rods food the size of my pinky nail every other day The tank has a Sapphire skimmer as well.

I would kill the lights untill the cyano dies off then resume with 1/2 duration lighting and adjust until corals, coraline, and other desirables keep the cyano away.


my .02

This could leave the tank with no lights for weeks. I have cut back the light period already.

 

[Anonymous]

...


This could leave the tank with no lights for weeks. I have cut back the light period already.

I predict it will take no more then a week and probalby only 3 days for the cyano to die off.

Also are your nitrates undectable? If so I would dose just a pinch of calcium nitrate every so often to bump the nitrates up to 5-10 ppm or so.

my .02

 

[Len]

I've never had problems with big water changes when using the same salt mix and mixing it to the same salinity and temp. However, there's a school of thought (championed by Julian Sprung IIRC) that water changes are a bad idea with cyano and dino blooms because they add trace elements that fuel their growth. I'm not sure I totally agree. However, you might want to try changing/adding GAC and GFO first. These helped get my nutrients under control. I had bad dinos and some cyano last month, but it's mostly gone away now that I changed the GAC and added GFO. Vodka dosing could also work, but just be careful with it (less is better than more when dosing Vodka).

GAC and GFO need a food flow of water through them to work? There is no where good in the tank to get good flow through them.

GFO needs virtually no flow. Any cheap reactor and a 10-20gph mini powerhead is everything you need to get GFO working properly. GAC needs more flow, but nothing drastic. Even 50gph through GAC is good (the lower the flow, the higher the efficiency but the slower the processing rate).

 

[Len]

...


This could leave the tank with no lights for weeks. I have cut back the light period already.

I predict it will take no more then a week and probalby only 3 days for the cyano to die off.

Also are your nitrates undectable? If so I would dose just a pinch of calcium nitrate every so often to bump the nitrates up to 5-10 ppm or so.

my .02

You want Rob to increase nitrates?! 8O

 

[Anonymous]

I've never had problems with big water changes when using the same salt mix and mixing it to the same salinity and temp. However, there's a school of thought (championed by Julian Sprung IIRC) that water changes are a bad idea with cyano and dino blooms because they add trace elements that fuel their growth. I'm not sure I totally agree. However, you might want to try changing/adding GAC and GFO first. These helped get my nutrients under control. I had bad dinos and some cyano last month, but it's mostly gone away now that I changed the GAC and added GFO. Vodka dosing could also work, but just be careful with it (less is better than more when dosing Vodka).

GAC and GFO need a food flow of water through them to work? There is no where good in the tank to get good flow through them.

GFO needs virtually no flow. Any cheap reactor and a 10-20gph mini powerhead is everything you need to get GFO working properly. GAC needs more flow, but nothing drastic. Even 50gph through GAC is good (the lower the flow, the higher the efficiency but the slower the processing rate).

Its a Biocube - No where for a reactor. The sump is there to hide the pump/heater only.

 

[Len]

I've never had problems with big water changes when using the same salt mix and mixing it to the same salinity and temp. However, there's a school of thought (championed by Julian Sprung IIRC) that water changes are a bad idea with cyano and dino blooms because they add trace elements that fuel their growth. I'm not sure I totally agree. However, you might want to try changing/adding GAC and GFO first. These helped get my nutrients under control. I had bad dinos and some cyano last month, but it's mostly gone away now that I changed the GAC and added GFO. Vodka dosing could also work, but just be careful with it (less is better than more when dosing Vodka).

GAC and GFO need a food flow of water through them to work? There is no where good in the tank to get good flow through them.

GFO needs virtually no flow. Any cheap reactor and a 10-20gph mini powerhead is everything you need to get GFO working properly. GAC needs more flow, but nothing drastic. Even 50gph through GAC is good (the lower the flow, the higher the efficiency but the slower the processing rate).

Its a Biocube - No where for a reactor. The sump is there to hide the pump/heater only.

TFO's Phosban reactors are cheap and small. They can be used as a hang-on (which I don't think you can do, but I dunno if there are biocube mods), or you can plumb it remotely. You can even run it inside the tank for now until your cyano problem is fixed.

 

[Anonymous]

its a biocube - tank is too small for all that,. No where to run externally - safely.

 

[Anonymous]

...


This could leave the tank with no lights for weeks. I have cut back the light period already.

I predict it will take no more then a week and probalby only 3 days for the cyano to die off.

Also are your nitrates undectable? If so I would dose just a pinch of calcium nitrate every so often to bump the nitrates up to 5-10 ppm or so.

my .02

You want Rob to increase nitrates?! 8O

No I want him to kill the lights. :lol:

But if nitrates are unmeasureable the cyano is getting it's nitrogen from nitrogen gas. Bumping up nitrates just a tad would feed the corraline and corals which consume nitrates. And those would help starve the cyano of phosphates.
Calcium nitrate just seemed a logical addition.

But just killing the lights and allowing the cyano to die off returns the nitrates as well. plus at that point the cyano is also gone.

my .02

 

[Len]

No I want him to kill the lights. :lol:

But if nitrates are unmeasureable the cyano is getting it's nitrogen from nitrogen gas. Bumping up nitrates just a tad would feed the corraline and corals which consume nitrates. And those would help starve the cyano of phosphates.
Calcium nitrate just seemed a logical addition.

But just killing the lights and allowing the cyano to die off returns the nitrates as well. plus at that point the cyano is also gone.

my .02

Any literature I can read on about adding nitrates to reduce cyanobacteria? It makes no sense to me (both from a logical and factual standpoint).

 

[glassboxdesign]

Nitrogen limitation in a biocube is highly unlikely. Additionally, hobbyist test kits do not have the precision or resolution to take a zero reading with such seriousness.

Also -- Be carefuly with adding organic carbon sources, it can further fuel cyano bacteria.

 

[Len]

Nitrogen limitation in a biocube is highly unlikely. Additionally, hobbyist test kits do not have the precision or resolution to take a zero reading with such seriousness.

I can't see nitrogen (in whatever form) being limited in any closed system unless you do something purposeful to effect this result. I'm still not clear what bob's premise is.

Also -- Be carefuly with adding organic carbon sources, it can further fuel cyano bacteria.

Good point. I've been focused on dinos in my own tank, so i (wrongfully) lumped the two together.

 

[Anonymous]

Any thoughts on why Rob always seems to have issues with algae and cyano? He's had this problem for years. First with his old tank (numerous threads) and now with his new tank.

 

[Anonymous]

The nutrients the cyano is using may be localized in the rock.

 

[Raskal311]

Go for it, i've done three 100% waterchange in a 29gal bio cube before without any issues. I do 100% waterchange all the time in small tanks.