Losing fish and big ph drop today

[david day]

Hi all, I'm definitely having some problems here. Last Friday I finally put fish in my newly cycled system. 2 dozen small (1 1/2- 2 inch) gold fish. On Saturday I put another dozen in. Problem is I have lost 2 or 3 every day since. Today I get home and 4 were gone! Before I starting putting fish in h2o levels were: Amm-0, Nitrite-0, Nitrate-40 ppm, ph 8.0 ( this was at 8.2 the day before and I added 1 tsp. API ph down sulfuric to bring it down). 50 gallon. Check levels every day and they have remained fairly constant with Amm reading at 0.25 ppm or so. On Monday I mixed 1/2 capful of Maxicrop w/ iron into the system to bolster my young plants. Today the levels are a bit odd. Amm-0.25+, Nitrite-0.50,nitrate- 40+ ppm ph- 7.4. Could the MC have something to do with such a big drop in ph? Or an increase in Nitrite? At which Nitrite level should I really start to worry. This system is well aerated and runs about 70 F. My inexperience is shining through! Thoughts? 

[TCLynx]

More likely, the system is just cycling further.  As the bacteria do their job converting the ammonia and nitrite to nitrate, they use up the buffering capacity in the water and will naturally acidify the system.  As the pH drops the bacteria get a little shook up by the change and you sometimes see some spikes if the pH changes too far or too fast.  keep the feeding minimal when you see ammonia or nitrite climb and if it gets too high stop feeding.  Keep an eye on the pH since if it drops too low, you might want to do something to buffer (like probably top up a little at a time which will probably help keep your pH from dropping too low since it sounds like you probably have kinda hard water.)

 

Make sure there are no dead fish hidden some where and that there isn't a build up of uneaten feed or fish poo in the fish tank that might be responsible for some of your issues.

[david day]

Thanks TCL, i do have hard water here. You are a big help.

TCLynx said:

More likely, the system is just cycling further.  As the bacteria do their job converting the ammonia and nitrite to nitrate, they use up the buffering capacity in the water and will naturally acidify the system.  As the pH drops the bacteria get a little shook up by the change and you sometimes see some spikes if the pH changes too far or too fast.  keep the feeding minimal when you see ammonia or nitrite climb and if it gets too high stop feeding.  Keep an eye on the pH since if it drops too low, you might want to do something to buffer (like probably top up a little at a time which will probably help keep your pH from dropping too low since it sounds like you probably have kinda hard water.)

 

Make sure there are no dead fish hidden some where and that there isn't a build up of uneaten feed or fish poo in the fish tank that might be responsible for some of your issues.