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MKurpicski
08/18/2011, 01:23 PM
I did a 20% water change on my 55gal salt tank to bring my salinity down along with my nitrates. I had a 20ppm nitrate and salinity level of 1.027 before the change and afterwards my nitrates spiked to 40ppm and salinity level dropped to 1.022??????

mk

spieszak
08/18/2011, 01:31 PM
If you didn't stir up sand or detritus, check your water source/holding containers

MKurpicski
08/18/2011, 01:32 PM
Sand did get stirred up.

mk

sporto0
08/18/2011, 01:40 PM
The only way your salinity could drop like that is because the replacement water salinity was too low, the nitrate spike is understandable from the substrate being stirred, do another water change without mixing up the bottom this time & make sure your salinity is correct before you add any water.

demonnite57
08/18/2011, 01:45 PM
a good method for adding the water is to place a bowl or plate to diffuse the water stream (if you're doing it from bucket straight into DT). hold the plate a little underneath the water line (or set it somewhere where it won't disturb anything) and pour the water onto the plate/bowl

Palting
08/18/2011, 02:00 PM
I'm not so sure about the "don't stir the substrate" part. I agree that the nitrate spike is from disturbing the substrate, releasing the detritus that then went on to be converted to nitrate. BUT, that's what you want to do: remove the detritus. IMO, best is to vaccuum the substrate to get as much of that detritus out, and also to release it into the water column so it can be converted all the way to nitrogen gas by your biolgical filters.

How old is the tank? How deep is your substrate? What's your biological filtration?

sporto0
08/18/2011, 02:13 PM
Well since he already caused a nitrate spike, I wouldn't do it again right away by stirring it up again, I would hope that from experience now, he will know to periodically clean the substrate without causing such spikes.

MKurpicski
08/18/2011, 03:15 PM
The goal was to stir up the substrate, I have a red algae on it that I was trying to remove from the bottom, the reduction of salinity was on purpose, I did not mean to come down quite that much but was intending on bringing it down to ~1.023 to be in a comfortable level for my current livestock and the corrals I'm looking to add to the tank.

mk

sporto0
08/18/2011, 03:32 PM
The goal was to stir up the substrate, I have a red algae on it that I was trying to remove from the bottom, the reduction of salinity was on purpose, I did not mean to come down quite that much but was intending on bringing it down to ~1.023 to be in a comfortable level for my current livestock and the corrals I'm looking to add to the tank.

mk

Ok, then I'm a little confused, did you think the nitrate spike caused the salinity drop? If you were trying to drop it, then you knew why it came down so why did you add that to your post? I would add some sand sifters to help you clean your sand bed, it might help reduce the nitrates being released all at once.

MKurpicski
08/18/2011, 03:48 PM
I added the salinity detail to my post to include a complete accounting to what lead up to the spike. Please elaborate on sand sifter??

mk

sporto0
08/18/2011, 04:02 PM
Nassarius Snails, Cerith Snails, small Bristle Worms, Brittle Starfish, Hermit crabs etc. are all sand bed cleaners.