tank update: brown algae appearance

[Tackett]

hey all, this is an update to my previous thread that described my many problems that could be remedied with simple more frequent water changes. The last thread I posted on this update told of changing tanks from the 29 to a 55 gallon. I started changing water using wal-mart bought reverse osmosis deionized water (or at least it says so on the label.) 15 gallons (30% of 50) every week, like clockwork, on fridays after work. Before I started to continue using the wal-mart water, I took a gallon down to a water laboratory that I know and had it tested for a few paramaters:

TDS; <.001ppm
DO; 2.6%
PH; 6.98
Phosphate (Po4); 0.01ppm
silicates; <.001ppm
Nh4; .002ppm
Nh3; <.001ppm

These were the chosen tests (all I could afford to have run) This led me to conclude that the water I was using was fine for the time being until I could get a RO D/I unit. The salt that I have been using is the ocean salt. I started having one small problem with the oceanic salt after having moved the small tank. The alkalinity was plummetting about everyother day. (small water changes of 5 gallons remedied this.) I was getting mighty tired of water changes everyother day. Wanting to leave this a pure water change experiment I decided the best way to try to fix this problem would be to add some Kalkwasser. So for about a week I slowly dripped Kalk into my sump using a small 10 gallon trash can placed on a table above the sump, airline tubing and a gang valve used to adjust drip amount. This solved the alkalinity problem. So this experiment has proved at least one thing and that is oceanic salt buffering capacity is very low, agreed? Now. This week (about tuesday) I did a phosphate test and wound up with a reading of 0. This was after I had gotten steady feasable readings for a while. This made me rais an eyebrow and I kept an eye on the tank for a few days. From tuesday on, I came home to a tank becoming steadily encrusted with brown and green slime algae, no hair algae though, that problem seems remedied. Any suggestions on where the algae has come from, how to get rid of it, or if it will run its course in due time? Does anyone see anything wrong with my methods? Should I switch salts to IO to solve the alkalinity problem or keep adding Kalk?

 

[Anonymous]

Hi Tacket,
Ok. The PH issue. Before you dose with kalk, which isn't necessarilly a bad thing, if you know why you do it, check this out. Many times a PH issues has to do with a lack of dissolved O2 in your water. That being said. Do a test. Stop the kalk for a bit, and when you PH goes low, try this. Take about a quart of your water out of your tank. Take an airstone and pump, and put it in the quart of water for about 1/2hour-45minutes. Then, test your water again for PH. If it rises, then you know you have an O2 problem. How do you fix? Circulation and skimming.
Brown/diatom algae. If you've got a fairly new tank, this is normal. It will run it's course. However, this could be why you are getting a reading of 0.0 phosphates...because the diatom is using it. Just make sure that you are dumping in pure water with your water changes.
Lastly, don't treat your tank like a science project. Relax. You'll get there soon enough, but every time you dump more stuff into your tank (including water changes), you change the bio-chemical status of your tank.
HTH, :wink:
~wings~

 

[Tackett]

thanks for all the info man. I couldnt imagine my DO2 level being low, I have a tidepool biowheel for filter and a a seaclone for a skimmer (the one for 100 gallons, dont know the model number off the top of my head.) but I guess anything is possible, I will check the DO2 level when I get home like you said. (good info btw.) Should I not change 30% every week? what is your water change suggestions? I ran all those labs on the wal-mart water just to make sure that I didnt have any surprises in my source water. Its not a new tank, so I dont have a clue why there are diatoms, they seemingly just appeared, they had to come from somewhere right? hmm... everything in the tank seems to be doing well so I am not too stressed about it, the turbos are super happy now Do you think that the diatoms will go away eventually if I keep doing things the way that I am? (minus the kalk)

 

[Anonymous]

Hey Tacket,
Your biowheel could be the source of your diatom problem. If it's not cleaned, it's manufacturing nitrates like crazy, and your diatoms are enjoying every minute of it.

Some people here are nuts about changing water. Personally, I don't do it because I do add a good amount of water per day for evaporation. If I do a water change, it's once every 2 months or so, and only about 7% of total water volume (not quite 10%). I've had the best success by just leaving the tank alone, and being very consistent with evaporation, skimming like crazy, and keeping foods/nutrients to a minimum.

HTHs,
~wing~

 

[kandiru]

sounds like the set up is fairly new

having brown diatom algae blooms is normal in a newly set up tank

just keep wiping them and stick to your water change routine for now and they will go away by themselves

good luck