29 replies to this topic

[Sean Phillips]

One of my 20s (24x12x16) has 3 Redside dace, 3 Silverjaw minnows, and 2 bluefin Killies in it. The minnows were sick for a while when I added them (my fault, I didn't QT) but they've all long since recovered. Now while not QTing them was irresponsible on my part, I also at the same time had a large darter die-off from Cyanobacterial infections. I'm guessing the minnows weren't affected because they're suspended in the water column whereas the darters are on the bottom. It appears that the tank is growing either Cyanobacteria or bright green algae and I can't tell the difference, either way I've been scraping it off and siphoning it. However with all the problems I've had with this tank in the past, I kind of want to treat these guys to a mild degree before I add them into their new home in about a month (a 75g) with my collection of perfectly healthy darters and native Killies. What would be the best mild cure that wouldn't harm them at all if they aren't sick, which they proabaly aren't, I'm just being safe?

On another note, I'm going collecting either myself or with one or two other gpasi members this weekend at my local creek since they were excited when I told them where to find Silverjaws, redsides, and Johnny darters around here. I plan on grabbing another 2-3 Redside dace and another 2-3 Silverjaw minnows to increase the size of my schools. Would it be better for me to either QT them in a 10G with three 2.5-2.75" yellow bullheads or put them into the 20 with my current Silverjaws and redsides. Their ultimate home will be in my 75 in a month.

Thanks for the advice!

[Sean Phillips]

Would salt make a good treatment or are any of those species sensitive to it? Some people have salt in there tanks regardless for health benefits which is why I'm wondering.

[Matt DeLaVega]

I think everyone should have salt in their tanks unless they are planted. Without exception, you should have salt in your collecting bucket. A tablespoon of non-iodized salt without anticaking agents per 5 gallons is fine even with catfish in my experience. That is just my opinion.

Also collecting fish during colder months is much better. Less pathogens, and lower parasite load, as well as less stress on the fish, as long as you do not warm them up too quickly. Native fish can deal with rapid cool downs better than they can rapid warm ups.

I would be surprised if cyanobacteria is causing your problems, Maybe Gerald could help here.

[Matt DeLaVega]

Hydrogen peoxide will kill cyanobacteria.

[Sean Phillips]

Did a 50% WC and added 1.75-2 tablespoons of total salt to the new water. I don't think it's Cyanobacteria and I'm pretty sure it's just green algae as at certain times of the day, the sun shines directly into half of the tank which is probably why the algae is such a bright color.

Now as far as new fish goes, I should be heading out in roughly 30-50 minutes to try and get some more dace and minnows. Would it be better to out them right in the 20 since like you said, there's less of a risk of disease in colder months or QT them in a 10G with yellow bullheads (the minnows should be far to big for the bullheads to eat)?

[Matt DeLaVega]

I may be a dummy, but I rarely quarantine. In winter, pretty much never. But I've always salted heavily and changed water weekly.

[Sean Phillips]

Well, no luck collecting today regardless. Most of the spot was frozen so I threw my minnow trap in and caught a few chubs on power bait until I was freezing and when I pulled the trap 30 minutes there was nothing in it. I'll head back out with my seine next time we get weather that's in the 40s and the ice thaws.

[AussiePeter]

FWIW, catfish like channels take up to 10-15 ppt of salt.  That's just shy of half sea water.

 

Cheers

Peter

[Matt DeLaVega]

FWIW, catfish like channels take up to 10-15 ppt of salt.  That's just shy of half sea water.
 
Cheers
Peter

Yes they salt catfish aquaculture ponds heavily to combat brown blood disease. So I have always thought the fear of salting catfish was unfounded, and in my experience it is. Though I have never salted to 50 percent sea water. Thanks for the input.

[strat guy]

Cyanobacteria- Cyano bacteria show up for four reasons- low flow, too much light, too high organics, and too low nitrates. First, syphon everything off and do 50% water change. Get as much BGA and detritus cleared up as you can. Decrease your lighting time to 6-8 hours a day with a timer, and if you have sunlight, think about killing the lights during the portion of day the sunlight comes in. If you have low flow, add a powerhead, and try to direct it toward low flow areas. Nitrates shouldn't be an issue in a well stocked tank. Next, black out your tank for 48 hrs. No light. after the blackout period, spot kill any remaining BGA with Hydrogen peroxide and a turkey baster or syringe. Make sure to kill the water flow for 30 min before treating so the peroxide will rest on the BGA. Let the peroxide work for 2 hours and then turn the pumps back on. Peroxide turns to water and oxygen over time and is harmless in small quantities. Remember the reasons it shows up, and try to focus on being consistent with those areas or it will come right back.

 

Other algae- These show up due to excess nutrients in the water column. Do yourself a favor and add some plants. They'll outcompete the algae for nutrients. Hornwart and Elodea are easy and float. Elodea is a good food plant for fish to graze on and will invite infusoria for smaller fish and babies.

Edited by strat guy, 03 February 2015 - 04:59 PM.

[Sean Phillips]

Cyanobacteria- Cyano bacteria show up for four reasons- low flow, too much light, too high organics, and too low nitrates. First, syphon everything off and do 50% water change. Get as much BGA and detritus cleared up as you can. Decrease your lighting time to 6-8 hours a day with a timer, and if you have sunlight, think about killing the lights during the portion of day the sunlight comes in. If you have low flow, add a powerhead, and try to direct it toward low flow areas. Nitrates shouldn't be an issue in a well stocked tank. Next, black out your tank for 48 hrs. No light. after the blackout period, spot kill any remaining BGA with Hydrogen peroxide and a turkey baster or syringe. Make sure to kill the water flow for 30 min before treating so the peroxide will rest on the BGA. Let the peroxide work for 2 hours and then turn the pumps back on. Peroxide turns to water and oxygen over time and is harmless in small quantities. Remember the reasons it shows up, and try to focus on being consistent with those areas or it will come right back.
 
Other algae- These show up due to excess nutrients in the water column. Do yourself a favor and add some plants. They'll outcompete the algae for nutrients. Hornwart and Elodea are easy and float. Elodea is a good food plant for fish to graze on and will invite infusoria for smaller fish and babies.

Thanks for that. I give the tank about 6 hours of artificial light a day although I don't think it's Cyanobacteria again, looks slightly different. I had hornwort and water sprite in there for a time. Lost the water sprite fast due to the Cyanobacteria and the hornwort has just recently been completely choked out by algae. I'm terrible at keeping plants alive that aren't plastic, which is why spawning mops are indispensable to me being a breeder .

[strat guy]

If you can't keep hornwart, something is wrong. Hornwart should last under even the worst conditions. Even in low light, it will live on as just a stem with only a few leaves. Where is it that you're seeing the algae? And I just got rid of a bunch of it too, mine was bright green as well; don't trust the color. In saltwater tanks, its sometimes red even.

 

 

I guess if you can't keep hornwart alive, maybe it is your nitrates. Plants can't survive long without nitrates. If you've got a testing kit, test your tank water as well as the source you use for your refills, probably your tap. If your nitrates are reading 0-5ppm, you're great for a no-plant tank. If you're trying to keep plants, then this is bad news, and bad news again if you've actually got BGA. You want that nitrate level up in the 20-30 ppm range.

 

If you've got any plant questions, you can shoot them and I'll give you some info as I'm able.

[Matt DeLaVega]

I have really hard tapwater. Comes from wells deep in limestone. Ph of 8.3 or so. I found that rainwater worked much better with green water cultures than my tapwater. Just a personal observation.

[gerald]

Low measurable nitrate concentration in the aquarium water doesn't necessarily mean your plants are starving.  There may be plenty of ammonium & nitrate production going on, by animals and bacteria, and the plants are quickly absorbing it as it is produced, so there's not much left to measure in the water, but plenty held in the plants' tissues.  Most plants are just as happy with ammonium as they are with nitrate -- many actually do better with ammonium, which requires less energy for the plants to process.  Go measure nitrate in a lush plant bed in a lake or river - it usually wont be anywhere near 20 ppm unless it's getting sewage or farm runoff contamination.  (It may be higher under the substrate). The 20-30 ppm nitrate that some people use with CO2 supplementation is for maximizing growth, providing more than the plants can efficiently use.  Do you judge whether fish are getting enough food by how much uneaten food is floating around the tank?

 

Strat Guy wrote:   Plants can't survive long without nitrates. If you've got a testing kit, test your tank water as well as the source you use for your refills, probably your tap. If your nitrates are reading 0-5ppm, you're great for a no-plant tank. If you're trying to keep plants, then this is bad news, and bad news again if you've actually got BGA. You want that nitrate level up in the 20-30 ppm range. 

[strat guy]

This is what Tom Barr suggests. Especially when combatting BGA. Nitrates need to be up if you're fighting BGA.

 

As far as plant growth, the reason for keeping the Nitrates high isn't so your plants don't starve, but so that it doesn't become a limiting factor in growth. If you keep it in the 20ppm range, they'll all have as much as they need for whatever rate of growth they desire and something else can become the limiting factor, like light or CO2. Tom Barr suggests 1/8 tsp KNO3 per 20 gal per week in a non-CO2 tank. 

 

Either way, hornwart shouldn't die. That stuffs called a weed for a reason. Even in low light, it should live on, just with less leaves.

[gerald]

OK that makes sense, keeping nitrate high to favor plants over BGA in new tanks.  After the vascular plants are well-established and BGA has fizzled out, is there any reason to continue keeping nitrate above 20 ppm?  From a fish-health perspective, I would think the less nitrate the better, true?   The safe limit for drinking water is 10 ppm nitrate-N.  [Do aquarium test kits measure nitrate-N or the whole nitrate (NO3) ion?]

 

In my tanks hornwort dies or stops growing in very soft water - it seems to need a few degrees hardness.

[strat guy]

Actually, it has nothing to do with outcompeting BGA. Since BGA is actually a bacteria  (cyanobacteria) and not an actual algae, its doesn't compete directly with plants for nutrients. Low nitrates is just a factor for BGA, as I listed above. Low nitrates, low water movement, long photo period, and large organic buildup are all contributing factors for BGA to show up. Read my post above, the first step aside from a total blackout is to start dosing KNO3, some people suggest quite a large amount, up to 3 teaspoons a day for a 29 gal. I killed mine by doing what I mentioned above. I had all the issues at the same time- low flow, 14hr photo period, large amount of mulm, and no fish (I still only have 4 2.5" fish in my 100). Dosing KNO3 was the big factor. Since I have no fish in my tank right now, I just have to keep supplying it until I can get a good stock.

 

I believe test kits measure NO3+.

 

Yeah, hornwart doesn't like soft water, but then again no plant really does. That could be an issue for Sean as well. Good observation. In soft water tanks, I use limestone decorations as a buffer. We have a lot of that in Chicagoland.

[gerald]

So adding nitrate will suppress BGA growth even in a tank without any other plants?  ... weird, i wonder how that works ... something to do with N:P ratio I guess ?   However, I do think plants and BGA compete with each other for nutrients.  The sequence of chemical reactions in photosynthesis is similar whether it happens in a plant, algae, cyano, or lichen; their chloroplasts are pretty much the same. 

 

In my tanks, once a good crop of plants gets established and "balanced" with the fish load (whatever that means), BGA disappears or is reduced to just a thin line around the water surface edge.  (Except for the time I tried using hollow beef bones for spawning caves -- BGA loved that! -- phosphate source I assume).

[strat guy]

I don't know the rules about linking to other forums, so I'm cutting and pasting what Tom Barr has to say. On top of all this, read across forums, the #1 way to solve a BGA problem, plants or not, is dosing KNO3. Even once its gone, its best to keep your NO3 up in the 5-10ppm range for non planted and 10-20ppm for planted to keep the BGA from coming back, along with addressing the other issues like organic buildup. Even without a BGA issue, that concentration is good for the plants so that nitrates don't become a limiting factor in growth.

 

Here's Tom Barr:

 

 

Quote:

Originally Posted by Tsigoloeg 

I apologize in advance for sounding like a cantankerous old coot. 

Can anyone point to a definitive scientific (or at least putting on airs of such) work that is readily available? Seriously, did someone just read somewhere that some cyanobacteria have heterocysts that fix nitrogen and thus all must thrive in low-NO3?

The genus Oscillitoria is specific and what infest our tanks, and is a non heterocytic forming BGA. Rather than assuming low NO3 etc, the size difference alone in all algae point to this.

Algae and BGA's are not limited by N in planted aquariums.
Relative to plant, they have several orders of magnitude less demand for N.
Plants on the otherhand grow poorly/not at all, stunt etcwhen NO3/N is very low.

Many suggested low NO3 and heterocyst, I have always strongly argued against it because I actually can do algal and cyanobacterial taxonomy.
Several other reseach folks also have verified the taxonomic determination in the same lab I was working in. 
It's a very common FW genus.
See Sheath et al.
Also, try Google scholar for references.
 

Quote:

I only ask because I keep seeing this over and over on this forum, yet when I starved my 29 gal of nitrate the only visible minor colony of cyano in the tank, which rode in on a lotus I had just purchased, went away.

I have induced NO3 many times by starving the tank.
I confrmed it with a calibrated test kit.
Still, it does not say what causes BGA to grow and bloom.

You will not find a reference that says X causes Oscillitoria to grow. You might find some corrleation, not much is done with this genus with respect to aquatic macrophytes.

When deciding what consititutes a good fair test of whether something works or not, you first need a control and base line to compare to don't you think?

A 1/2 dead colony of a nice healthy mat would work best for comparing things and treatments to????

Obviously a nice thriving mat of BGA.

When inducing BGA, what would be a better baseline to induce BGA in a tank?
One that has good plant growth for the the last few weeks, no signs of issues, etc, then you manipulate one variable at a time or would a tank that's on the border line with little control of test, some different species here and there of algae(A sign of something wrong in the tank to begin with)???

Most hobbyist are not able to discern and implement a good test for algae.
Most lack the control and the ability to have baseline.
Most that complain are those that do have issues already 
The ones that do not have the issues etc tell them what to do, but they think they already have done it(they made this assumption very often).
 

Quote:

Now don't read too much into that fact as a causitive agent either, as I also starved PO4 at the same time, probably other elements as well but I wasn't paying attention to molybdenum etc. But I think that if the stuff really flourished in low NO3 environments as a cause-effect relationship, my tank would be smothered in it.

Many tanks do well with low NO3/PO4.
How confident are you that the tank is really low in NO3 and PO4?
What types fo testing methods, calibration methods do you use?

I know I can induce BGA in most tanks, but perhaps not all. I also know that virtually every tank's substrate sample I've ever looked at had Oscillitoria.

I think Oscillitoria is responsive to the plants, perhaps a biochemical stress they give, or form of leachate that plants give off when stressed.

I've also seen BGA bloom when the water is very high in organics and the filter's not been cleaned for a long time. 

But in each case, I've found counter examples also where Oscillitoria did not grow as well.

Still, the chances of folks having BGA due to NO3 is well correlated if you tally the total BGA reports vs the solved cases.

I have not had a BGA issue in many many years.
Enough to know that if due to chance alone, I should have had BGA if it where not due to KNO3 dosing.

Some have suggested it is K+ rather than NO3 from the KNO3.

Could be.

But generally, the evidence based on testing our tanks with calibrated test kits seems to point more to NO3 as the main cause, as few if any folks test their K+ that I know other than myself.

I'm afraid there is just not a lot of scientific research done with many algal species and BGA's in the contect of our tanks and plants etc.

There are many unknowns and correlations, we can say what it is not(falsification), but it's much harder to say what it is(verification).

I've found that doing the blackout and KNO3 dosing etc takes care of it and reinfestations do not occur each time I've done it for a friend or on my own tanks that I've induced BGA in. after 20X I start to feel comfortable about a method to control it.

Still, it's not a silver bullet either(Growing plants well seesm to be the only silver bullet there is). Some folks will always have algae issues for one reason or another. Some will not follow part of the method etc.
We make mistakes and often learn more from such mistakes.

You need to do some background reading, test and set some test up first before you argue. Thus far you have not presented much in the way of new support against low NO3 stunting plants and it might be low POI4 as you acknowldge, thus already you lack the control and have not actively tested/calibrated the test kits nor set up an experimental design.

I do encourage this. Make sure to verify your PO4/NO3, timing, the health before and after, and so forth when you do it.

Try and not base things on potentially confounding factors like not dosing and assuming that means the NO3 is low.

It might not be.
Or the PO4 levels, K+, levels or traces, CO2 etc.

I see the same stuff folks do also, but I knwo I need to be careful and make sure what I see is somewhat reasonable and I can rule out things like CO2, 
PO4, K+, etc.

All science has some degeree of doubt and should be viewed critically.
But it does work very very well nonetheless.

Regards, 
Tom Barr

[Sean Phillips]

Strat Guy, well the hornwort doesn't completely die, it just becomes almost nothing but the stem and maybe had a few occasional leaves left. It died in this tank because algae choked it out. It also is in the process of deteriorating in my 15 gallon because silt is choking it out and I have NO idea where the silt is coming from! I did a 100% water change and squeezed the sponge filter out in a bucket of tank water! rinsed the hornwort, and rinsed all the decor and by the time everything was back in and I filled it back up the silt was just as present as it was before I sphoned all the water out, been like this for months but the hornwort is surviving it, just not thriving. The only tank I'm having luck with his plant is my other 20 tall with Johnny darters and gambusia where it's barely growing (probably because of the cold water) but the stuff that's in there is doing great.