When I started cycling TDS was 30, should I drain and replace with TDS 0 water?

[kendrid]

As the subject says, my Ro was old and producing TDS 30 water. I replaced the DI and RO and it is now producing 0 water.

The tank just finished cycling and the nitrates are high so I need to do a big water change (ammonia and nitrites are 0). I have small feather dusters popping up on the rock and I have small white bugs (I assume pods) all over the place. I have also spotted a few random snails.

Should I drain it all the way and refill? If not what percentage should I change for my first WC. The tank is a 30 gallon. I am setting up a QT this weekend so fish will not be added for a while. I plan on starting a clean up crew soon.

Thanks!

[thegrun]

I would bite the bullit and make a 100 percent water change. If you make it quickly and match your tanks ph, salinity, alkalinity and temperature closely you shouldn't have issues. There is a chance not making a large water change will cause an algae outbreak. There is no good way to determine what if any problems the old water will cause, to be safe I would change it all

[bnumair]

Yes 100% water change.

[SoLiD]

No fish... Then, change as much as you can. Also start testing for Phosphates before and after the water change.

[kendrid]

Thank you for the quick replies. I have a 55 gallon container that I make my RO in (I have a discus tank). I will make water overnight, transfer it to my salt mixing tub and try to match the tank params. If it starts a mini cycle it isn't a big deal since I don't have plans to add anything but snails anytime soon.

[thegrun]

You should not have a mini cycle if you make the change quickly before the rocks start to dry out.

[kendrid]

You should not have a mini cycle if you make the change quickly before the rocks start to dry out.

I should be able to drain and fill the tank in 20 minutes. Thanks again for all of the help.

[MARINECRITTERS]

I would personally remove everything, bleach your rock and sand and do a 100% water change, the water you were using could of been absorbed into your rock, all of those contaminates such as copper, metals, phosphate, will lead to algae and an un healthy tank.
Start you aquarium fresh.
Also I would purchase a RODI unit from brs, RO units usually won't cut it.

[sleepydoc]

If Nitrates are high, it hasn't finished cycling.

Marine critters - he has a DI unit, it evidently had old/depleted resin, though to produce TDI 30 water.

Problem is you don't know exactly what was in the water, but I think removing everything is overkill. Even in the worst cast that there was some copper or phosphates in the water, it's unlikely that enough has leached into your rock to cause significant problems just from the 100 gallons you used when cycling. If the OP has 0 TDS water now, he/she should be fine.

[cap032]

Agree with the above post.......accept for Nitrates. Nitrates do not have to come down on their own to complete what we consider the cycle. If you can run ammonia up to 2ppm and convet both it and nitrite to 0ppm in about 24hrs, you had a good cycle.

[kendrid]

Sleepy - my TDS meter was way off calibration so while I thought I was making 0–1 TDS water it was really 25-30. I only used 25 gallons of TDS 30 water to cycle the tank. I have my 0 water made and I will be draining and filling in a few minutes. I ran Purigen and Phosguard during the cycle if that matters.

Cap - after filling it tonight and testing everything I am going to add ammonia to test the cycle time. The first time I added ammonia I overdosed it to 10ppm. It came down after a week and the nitrites took two weeks. I added 3ppm a little over a week ago but then I left on a vacation so I don't know how long it took to convert to nitrate.

Thanks for all of the opinions and replies.