Iron dosing causing hair algae.

Re: Iron dosing causing hair algae.

For what it's worth, I had the same issue for a while but I wasn't being overly scrupulous on the dosing schedule and the CO2 was a bit low. Once I brought CO2 back in line, the hair algea basically disintegrated (pretty cool to watch, actually.) I've found that *any* time I have algea and I'm following the ferts pretty closely that insufficient CO2 has been the problem.

2 cents...

 

Re: Iron dosing causing hair algae.

I have seen the same thing you are talking about. It happened on the tank I set up two years ago and again on the tank I set up some months back. I really didn't understand why it seemed that the iron was causing algae, but I dosed less Iron and added as many Amano shrimp as I could afford and I had less problems. As time went on and the tanks matured I "pushed the envelope" so to speak and started adding a little more and more Iron until I was dosing what (if not more) than what I was dosing before. Not sure why this happened, but like I said it happened twice for me on two separate tanks. At least the second time I knew what it was right away.

That said I think Tom has a point on C02. Thinking back I was having issues the second time with Co2 (probably the first time too, but I was too much a noobie to know). Like you I was using a controller, but I think that was the problem. I have since removed the controller portion and just have a constant bubble rate going with a timer to shut off at night. I have found it to be a much better way to deliver C02 consistently day to day.

 

Re: Iron dosing causing hair algae.

Everyone I know that dose a lot of iron get hair/thread algae, given low macro and/or CO2-levels. They even smell of iron when you pull them out.

One thing I don't understand, question number 1: If I have low and jumpy CO2/macro-levels and have no thread algae, I dose iron and immediately get iron smelling thread algae - why isn't the iron the actual cause or even the trigger/inducer?

Question number 2: Is thread/hair algae better at fixing iron, like diatoms is very good at storing PO4?

 

Re: Iron dosing causing hair algae.

Did you end up testing CO2 some other way? Or did you just increase it and see that the fish were still fine.

 

Re: Iron dosing causing hair algae.

Definitely agree that the CO2/PH/KH charts can be a bit miss leading, as can the tested values for PH/KH. Currently I have a measured ph of 6.2 and kh of 5 so supposedly CO2 of 90ppm or so. My tap water has virtually 0 KH so I have to add sodium bicarbonate, I do this by weight to a known amount of water so the KH value should be fairly accurate, the Ph is tested with a reasonably well calibrated meter.

Anyway the point is that regardless of what my actual CO2 value is I got to the current PH/KH values by slowly upping the CO2 until the fish started looking stressed (around ph 6 – 6.1) then backing off slightly. Obviously this process needs to be done very carefully.

When I first set the tank up I had hair algae and it did seem to increase with the addition of Fe but importantly I wasn’t adding PO4 or NO3 at this stage, as well as using a dodgy ph probe which meant that CO2 was much too low. I found that fixing the NO3, PO4 and CO2 levels along with removal of visible algae fixed things pretty quick. A pair of rosy barbs helped remove the hair algae quite quickly.

As an aside; I am interested in this idea of a 1 unit PH drop. My water is currently 7.8 after being stood for 24 hours so a drop of 1.6. I would imagine that the amount of CO2 needed for a drop of 1 unit will still be linked to the waters buffering capacity so there will be differences between tanks. What do people think?

Regards
Neil

 

Re: Iron dosing causing hair algae.

In a tank of water containing alkalinity in the form of carbonates only, and acidity in the form of carbonic acid only, the equation that gives us ppm of CO2 is: CO2 (in PPM) = 3 * KH * 10 ( 7-pH ) . If you solve that equation for KH, assume that KH is constant whether the water is outgassed or not, you get: KH = CO2(degassed)/3*10exp 7-pH(degassed). Substitute that in the original equation: CO2(in tank)=CO2(degassed)*10exp[pH(degassed)-pH(tank water)]. Or: CO2(in tank)/CO2(degassed)=10exp{pH(degassed)-pH(tank water).]

So, the result is independent of KH, as long as the KH remains the same for the degassed water as for the in-tank water. And, if the pH drops by 1.0, the in tank water has 10 times the CO2 as the degassed water, which by my experiment is about 3 to 4 ppm.

 

Re: Iron dosing causing hair algae.

Thanks for that, I get it now. With a drop of 1.6 this suggests i have either 95ppm of co2, bad ph readings or less than 3ppm in the degassed water. While i'm reluctant to make any big claims about the accuracy of my ph measurments i'm inclined to believe that my co2 content is quite high due to the fact that it is pretty much on the limit of what the fish can take, and this level was reached slowly and in a controlled manner.

It would be interesting to hear of any references people may have for upper co2 limits for acclimatised fish at given temperatures and oxygen concentrations.

Neil

 

Re: Iron dosing causing hair algae.

Measuring PH accurately isn't easy. Using the hobby kits, like Aquarium Pharmaceuticals kit, requires judging between two or three colors, one sample of which is printed on a white glossy card, and the other is in a round clear tube. Anyone who can pick out the color (PH) within 0.1 should be an artist! Even doing so within 0.2 is very hard except for a small range of PH's. So, as accurate as this method is in theory, in practice it gets extremely iffy. And, a PH difference of 1.3 means twice as much CO2 as a difference of 1.0. I guess this is an argument for buying a PH meter.