Water Changes.....Too much, Not enough???

[saltyfishdude]

I have just started changing more water per week than I used to (5 gallons week). I have approximately 100 total gallons of water in my system. I Now change 15 each week. However, I have the home ro / di unit and plenty of salt, and I would like to bump it up to 20 - 25 gallons per week..................

My question is, does anyone agree that this would be fine and I wouldn't be changing too much, or has anyone had any bad experiences changing 25 - 30 % a week. Please let me know what you all think...............

Keep in mind that I only have four soft corals in terms of my coral inhabitants. And my alkalinity is about 10 meq / L, it was higher, needs to be about 5 meq /L. This is not because of the salt I'm using, for a while I was blindly adding buffer and builder every week, like a fool...............I have been working on it, past two week I've changed 25 gallons, but normally it is 15 gallons...................would like to keep it at 25

Again, does anyone have any feedback for me, I would like to do 25 gallons a week, approx. 25 - 30 %...................

[sir_dudeguy]

I see no reason to do that large of a water change, specially for only soft corals (and only 4 of them at that). the 15g (or roughly 15%) water change is plenty. Most people recommend only doing 10% water changes. The more water you change, the more you can mess up whats there. If you're testing both waters tho, then it really shouldnt make a difference how much you change as long as both tank water and new water is the exact same.

[saltyfishdude]

dudeguy, what levels in the "new and old" water are you talking about, temp, ph, what else?

[King-Kong]

I believe Anthony Calfo does 100% water changes every week on some of his SPS systems, so there's some point of view for you.

[mrrrkva]

What are you trying to accomplish other than lowering Alk? What kind of protein skimmer are you using. WIth soft corals I find the amt you are changing not necessary.

[mrrrkva]

I personally think 20% monthly is plenty. I think with a good skimmer and sump with Caulerpa 20% every 3 months is fine with softies

[sir_dudeguy]

ya, i'm with mrrrkva. 20% a month for SOFTIES alone is plenty. I find that the more i leave my softy tank alone, the better they do. I do like 1 water change per month (on a good month haha) on my 40 and its only like a 5g change. Not that much really. So i just see no point.

If you were to have sps and stuff that is actually hard to keep, then yes, i sure would do the amount you're doing.

and by levels, yes, i meant temp, pH, sg for the most part. I dont really think there are other levels that would matter if they're different or not.

[rssjsb]

Originally posted by sir_dudeguy
and by levels, yes, i meant temp, pH, sg for the most part. I dont really think there are other levels that would matter if they're different or not.

What about kh? I made the mistake of not checking this when I was changing salt mixes, and killed off one colony of sps and bleached several others.

It might not matter so much with softies, but I will note that the same episode did kill all the xenia in one of my tanks.

I'm sure someone will pipe up if I'm wrong, but I would be worried about doing that big a water change if (as your post indicates) the change water is that different from your tank conditions.

[gstuman]

I wish I could kill all the xenia in my tank!

I find that I only change 10% of my water in a 150 SPS tank every 2 - 3 months because it's way too hard to dose the Alk and Ca back to equilibrium with my Ca reactor otherwise. I notice worse effects when I do water changes than when I do not.

However, it should be noted that I don't have many fish and don't feed much.