prairielilly

My 20g is around 4.5 months old and currently holds 4 cherry barbs, 3 pandas and a dwarf gourami. Up til about 2.5 weeks ago it also had an oto (no cories at that time, they were in QT) at which time I noticed white stringy poo and started treating for internal parasites. Unfortunately lost the oto, everyone else got better, moved on, all's well.

During treatment (Jungle fizz tabs) I was doing 30% wc's every 48 hours as per directions, now I'm back to my regular schedule of 25% once a week. I test the water once a week - consistant zeroes for ammonia and nitrite, nitrate used to be around 5-10. So two days ago my nitrate was zero before I did the wc. Since that seemed odd I read some stuff on here about API's test kits and shaking the bottle more etc. Did that, got a reading of 5. Discovered the kit was made in 2003 - problem! I bought another test kit today made in 2007. I banged bottle #2 on the table for 10 seconds then shook it for 3 min then carried out the test as directed - nitrates 0-5 (it's now 2 days post-25% wc + gravel vac + adding 3 panda cats). Should also mention that since the passing of the last oto is the first time there's been significant (brown) algae in the tank.

So either I have an extremely efficient biofilter, a very understocked tank, algae is pretty efficient at removing nitrates, or...what? I've read that very low nitrates can result in cyanobacteria?? anything wrong here, does this seem odd or am I just getting newbie-scared again?

Shawnie

did you retest the ammonia and nitrites with the new test kit? sometimes meds kill the cycle and you have to start over which could be the "brown algae" (diatoms)...are there any live plants in the tank?

prairielilly

No live plants (well, algae....) It wasn't a test kit actually I had originally bought all the tests separately and I only re-bought the nitrate one bc the others were made in 2007 so not expired, I trust their results. I used the Jungle tank buddies which I've used before with no adverse effects on biofilter, I understood it to be anti-parasitic not antibacterial.

I think my cycle's ok (not crashed) and honestly I've never seen my fish happier - not complaining! it's awesome, just my head doesn't see why the nitrates would be so low. Maybe the cories are helping out by cleaning the bottom too? or bc I was doing so many freq wc's during the meds?

What do you think of skipping my weekly wc and monitoring all parameters to see if nitrates go up?

Worried about cyanobacteria!

Shawnie

deffinately more water changes will lower the nitrate...and bottom feeders also as they take care of any leftover food...I dont do weekly changes if my parimeters are on key...IMO too much cleaning is ALMOST, not quite, as bad as filthy tanks

agabr123

it's probably because of all of those water changes you did during the medication and then the other water change you did. once you get back to your regular schedule of weekly WC then your nitrates will probably be higher

EDIT: lol, ninja'd by shawnie

prairielilly

Wouldn't want to over clean the tank OK so just watch and monitor and it's fine So good to know!

I guess some reading up on cyanobacteria is in order too.

Funny I think, I joined this forum originally bc I had a new tank and didn't know anything and (among many other things) the water params and gravel vaccing got out of hand. Now the other end of the spectrum...makes me feel better though about adding my last 2 cherrys (in qt, was a little concerned it would overstock the tank - guess not).

Thanks for the insights!