water change question 1st time??

[muleycrazy]

Have sand & 45lbs of live rock in tank since 4/19 tested ammonia twice a day stayed at 0ppm, On 5/10 got 45 additional pounds of rock & CUC in tank. Ammonia is still at 0ppm. I tested my nitrite today & that is 0.25ppm & Nitrate is 10ppm. should i do a water change??? I was told the following "Do a water change when Ammonia and Nitrites are at zero, AND your Nitrates have increased above zero. So, in your case, wait a bit longer"

Tested 5/19, ammonia 0, Nitrites 0, Nitrates 10ppm How much of a water change should I do?? This will be my first water change?

[sponger0]

Typical water change is 10-20% water volume. How long has the tank been running?

[muleycrazy]

4/19/12 was when I added the liverock & sand & started it up

[ajcanale]

What are the details of your system... Size/Volume? Filteration? Sump?... and what are your plans with the tank? FOWLR, Mixed, Soft, SPS?

"Do a water change when Ammonia and Nitrites are at zero, AND your Nitrates have increased above zero. So, in your case, wait a bit longer"

-This is pretty accurate and a good rule of thumb to follow.

That said... 10ppm is a pretty low number for Nitrates following the initial cycle phase, which indicates me you have used live rock with very little die off, and done things properly.

I'd say shoot for a 50% WC.. to get those nitrates around 5... then test again to verify this. You can then start slowly adding livestock and additional CUC if needed. You will still see a lot of "mini cycles" as your tank progresses and adjusts to newly added livestock. Expect to see algae diatoms (brown) on the sand. Don't freak out, they should go away on their own.

Only other thing I'd say is to avoid SPS corals, and sensitive invertebrates and mollusks, until you are certain that all levels are stable.

[muleycrazy]

Thanks for the info! Here is my tank info

Size is 85 gallon, have a sump/Fuge with rubble rock & Chaeto & protein skimmer, plan on a mixed reef. Used live rock & sand from Tampa Bay Saltwater. Started getting the algae diatoms (brown) on everything 2 weeks ago. Diatoms are starting to clear up.

[ajcanale]

The chaeto should eat up some of the nitrates... provided that it has the proper conditions to grow. If so, 50% wont be necessary.

Call me crazy, but I think you are ready to start stocking (cautiously) my friend.

Make sure you have a stable temp. No major fluctuations between throughout any given 24h period.

[muleycrazy]

So would you do a smaller water change 10-20%? or not at all?

Temperature change has fluctuated from 76.9 to 78.5 the past 7 days.

Thanks for the advise!

[sponger0]

Ive never done more than a 25%. I dont see any reason why to do that even though you just finished cycling. The water is still going to go through some changes. So it should take care of the nitrates.

[muleycrazy]

ok thanks!

[ajcanale]

But the nitrates have to be removed somehow be it water changes, DSB, Algae/Bacteria growth, etc. It's the last step of the nitrification cycle.

Temperature change has fluctuated from 76.9 to 78.5 the past 7 days.

Not bad, but I would try to bring that low end up half a degree or so... 77.5 - 78.5 would be an okay range for temp swings, but the smaller the better.

[muleycrazy]

I just added the Chaeto 3 days ago, got a 6500K spiral fluorescent bulb on in the Fuge for it to grow. I will keep testing the nitrates. If they don't come down what would you recommend % of water change be done ajcanale??

[ajcanale]

I'd change out about a third to one half... once you get nitrates down to an acceptable level (<5ppm) then its just maintenance from there on out, which the Chaeto will help with. In my experience with Chaeto, it doesn't really make nitrates disappear, though I suppose in a fallow system it could. But there are many variables that it depends on.

I'm no chemist or biologist but I think the 3 main elements for Chaeto (or any algae) to grow are Nitrate, Phosphate, and Light. If any one of those three are not available then it will not grow. So if you have moderate nitrate levels, light, but no phosphate levels (unlikely) then it will not grow.

Just something to consider.

But back to the root question. I'd do a 50% WC. Then after you start stocking 5-10% weekly or 15-20% biweekly. As your bioload builds you will need to go with 10% weekly or 20% biweekly. Every system is different, so there's no perfect way of going about it.

[muleycrazy]

Thank you