View Full Version : dKh and Hair Algae?

03/11/2011, 07:43 PM
I am wondering if there is any science that supports my observations? I have a 24g nano that went through a massive hair algae infestation. The short story is that when I was dosed my tank daily to keep my dKh @ 10ish and Ca @ 420ish, I had a massive hair algae problem that went away after I quite dosing all together. After a year of dosing less frequently and no hair algae, I started dosing daily again because my numbers got very low...even though the tank appeared to be doing awesome and growing. And now the algae is starting to reappear.

I know the text book answer to algae issues is a nutrient issue but I am looking for info and opinions about a correlation between high dkh and hair algae. And high Ca and hair algae for that matter.


03/11/2011, 07:51 PM
Interesting. It's possible that the higher pH might be encouraging the hair algae, or maybe the supplement has a problem. I don't know what's happening.

03/11/2011, 08:11 PM
pH has always been consistent at 8.3 and I use ESV B-ionic. How is it possible that high pH encourages hair algae. We tend to focus on nitrate and phosphate when it come to nuisance algae, I want to learn more about how dkh, pH, Ca and Mag affect it.

03/11/2011, 08:31 PM
Well, mine may be related to nitrates due to bio balls which are slowly coming out, but I have a very slight hair algae problem. Could also be related to cyanbacteria I have only on my sand and I have just begun to dose due to low pH, mg and ca. My dkh was also low at 6. Just a mess ealier in the week but I just finished checking my tests and only nitrates are still up as the others are slowly improving. I swear since I changed salt things have gotten all out of wack. I sure hope I am on the right track cause this cyan is driving me crazy!

03/13/2011, 01:46 PM
Any other thoughts?

03/13/2011, 05:23 PM
I can't think of anything else that might be happening.

03/14/2011, 08:11 AM
i had the same problem have you ever checked your magnesium? i have a 44 corner tank and i got the test kit to check mg levels it sucks, very hard to understand mg test kit. ideal mg level is 1350 ppm so inlearning from testing mg levels fall fast so i dose weekly 1 cap full 5ml and i have no problemany more. I'd keep a check on red leg crabs or blue or what ever color you have and snails to eat that crap i hope this helps you out

03/14/2011, 08:37 AM
Imhotep75 - thanks for your help. I keep my Mag in the 1300's - aiming for at least 3 times my Ca. My hair algae really isn't an issue, if it gets any worse I'll just stop dosing the tank and it will go away. I want to understand how Alk, Ca and Mag feed hair algae in my tank. We mostly focus on nitrate and phosphate as fuel for hair algae.

03/14/2011, 08:56 AM
well i always have had zero phosphate and no nitrates i use ro water and i keep ca 450 or better alk i struggle to keep it above 8 i have to dose weekly and mg is the worst it is like mg is the first thing used up

03/14/2011, 09:24 AM
If I understand reef chemistry correctly, mag is not directly used by corals. Magnesium's roll is to allow high saturation levels for calcium and alkalinity. With high levels of magnesium, calcium and alkalinity are able to stay in super saturated levels before precipitating out. So your mag level is dropping due to the consumption of calcium and alkalinity.

I too never read nitrates or phosphates when I test for them. But when I push my numbers high it seems to cause the growth of hair algae??

Randy Holmes-Farley
03/14/2011, 10:23 AM
What exactly were you adding?

Some types of algae can use bicarbonate as source of carbon for photosynthesis, but that usually only becomes important if the algae are not already limited by other things (like N, P, iron, lighting, space, etc.).

03/14/2011, 11:50 AM
Thanks Randy for chiming it.

I use EVS B-ionic two part, usually in equal parts.

My nano has never tested any nitrates or phosphates with or without algae present. Are you suggesting that if the other factors that help nuisance algae photosynthesize/grow are low or completely limited then the algae will use bicarbonate..ie the alk buffer as the source for photosynthesis?

I run the nano bare-bottom, no filter media with the exception of a small sponge that is rinsed with weekly water changes, a protein skimmer and a auto top off. It's a mixed reef with one royal gramma a few crabs and snails. Lights are the Current NEP 6 bulb T-5 fixture, on a 8 hour white bulb photo-period and 10 hours blue bulb photo-period...so total of 10 hours lights on.

I currently dose 7.5 alk and 15 ca daily as an experiment to see if lower alk and higher ca will keep the numbers up and the algae at bay.