Water changes are definitely good but...

[jsousa]

My tank goes thru a weekly cycle after every water change. The day after the change all my SPS have pretty decent polyp extension but as the week goes on they start to retract, until, of course, my next water change.

What can be the reason for this? Could it be something being depleted, a specific trace element, or is it that nutrients build up over the week?

Has anyone experienced this?

My parameters are as follows:

ph: 8 - 8.3
KH: 8.5 - 10 (gradually increases throughout the week - could this be it?)
Cal: 430
Mag: 1400
PO4: .01 - .05 (Hanna meter)
NO3: < 1
Salinity: 1.25
Temp: 79


At each weekly water change, I replace about 10% of the water and dose Prodibio Biodigest, Bioptim and Reefbooster in order to keep my phoshates and nitrates in check. In addition to those doses, I have reactors filled with Rox carbon and GFO from BRS.

My feeding schedule consists of mysis, Rod's, and/or Rogger's reef food for the fish as well as mixtures of Coral Vibrance, Cyclopeeze, Coral Frenzy, Tropic Marin Zooton, Reef Nutrition Oysterfeast and Rotifeast for the corals.

Any help is greatly appreciated.
John

 

[stoney1118]

i have noticed my corals had huge polyp extension the day after a water change, i did them weekly to help keep water params good, now i run a reactor and only do a w/c once per month, sounds like maybe youre params are off but they read good! change salts! meybe?!

 

[divewsharks]

So you do a water change, alk is at 8.5, then throughout the week it rises to 10 at which point you do a water change and it drops down to 8.5?
If so yes that very well could be your issue. Stability is key to a successful tank. It looks like you are dosing ca/alk, I would cut back on the amount you are dosing.

 

[bmiller1234]

I agree with the above. Your alk shouldn't rise thru the week then fall at water change. If its dropping 2 at water change that's a major shock.

Maybe a little info on salt brand what salinity your mixing it at and what your dosing to pin point the actual problem would help.

 

[MrKite24]

Do some test of the water change water, too and make sure they match your tank water. Most of the time you will need to add supplements to your new water before you do a water change so it doesn't shock the system. It will also give you an idea of the quality of salt you're using.

 

[stevedola]

how big of a water change do you do? 10% of 156g, I dont think that a WC like that would cause youre problem. In order for your tank to drop from 10 dkh to 8.5 dkh from a 15 gallon water change your mixed water would have to be EXTREMELY low.

You must be dosing way too much or mixing the water under recommended instructions.

What type of salt do you use? mix some up and then test to know the starting levels of your new salted water. I know some companies have poor quality controls for salt, Ive had salts mix to 13dkh and others from the same company mix to 9 dkh next bucket.

 

[stevedola]

dosing and running that media could be your answer too. Im not familar with biodigest, biotim, or the others but maybe they are striping your water of the trace elements and essential nutrients. Then when you mix untainted water you replenish the water column.

you should check with someone that better versed in those chemicals.

have you thought of cutting back on feeding and reducing your dosing/GFO?

 

[jsousa]

Thanks for the quick replies. Sound like swinging Alk, as I had assumed was the culprit. As far as salt is concerned, I'm using Tropic Marin Pro Reef. I'll need to test the alk on my next batch. I'll keep you guys posted on the results. Right now, my tank alk is sitting at 9.5 since my water change on Saturday(3 days ago). I already lowered my doser to put out less. I'm using a RKE with BRS dosers for the essentials. BTW, when I tested my water on Saturday before the change, KH was at 11. (I guess I lied Didn't mean to just miscommunicated.)

Where are you guys keeping your alk currently? What brand of salt and how do you maintain it? Are you also using Kalk in your top off water? I am. Could be another issue, I guess. Should have mentioned that.

One other thing, because Stevedola mentioned it, and I would like to explore every possibility. I use Prodibio to keep my Nitrates and PO4 in check along with GFO and Carbon. Are you guys using anything to do the same? And for those using these products where are you keeping your alkalinity? If your not using and you are feeding your corals and fish heavily how are you keeping your nitrates and PO4 down?

I really appreciate the help guys.

 

[divewsharks]

Depending on your coral load, the kalk may be enough.
I believe most who dose prodibio (and like products), tend to keep their alk on the lower side.

 

[stanlalee]

what are you using for ca and alk maintainence. With alk RISING over the course of the week I assume you must be running a calcium reactor or dosing in which case some major adjustments are required. Otherwise the rise makes no sense, carbonates dont just show up out of thin air, should be dropping. With only 10% water changes I cant see anything being added or removed in significant percentages to change parameters or coral health. Perhaps the polyp extension is just a temperary response to stuff being stirred up a little in the water column after water changes, who knows.

 

[jsousa]

I'm using BRS Calcium, Alk and Mag. BRS Kalk too.

Checked my PO4 today too. It was a little high at .08. I moved some stuff around after removing 2 huge RBTAs yesterday and a little bit of stir happened.

If you guys aren't using a vodka, Zeo or another prodibiotic type product, how are you keeping your NO3 and PO4 down?

 

[stevedola]

I use TM pro reef salt and it consistantly mixes to 6.5 dkh when mixed to 1.025 sg which I add a little alk 2part to boost to 9dkh.

Ive been maintaining my levels at 415-420 ppm calc, 8.5-9.0 dkh, 1350 ppm mag. I personally dont use anything but a good skimmer and water changes to keep my no3 and po4 in check. I dont know about probiotic but if its anything like zeo then you are supposed to consistantly have your alk low (7-8 dkh) and run a low nutrient system which .08 p04 doesnt qualify as. \

I wouldnt think the kalk would contribute to your problem. Personally my course of action would be to stabilize your dosing and maintain your levels and see if you have a positive reaction to that. Then work from there. Too many changes can lead to even more problems IME.

 

[jsousa]

OK, I have adjusted my dosing. My tank is now at 9 KH. I'm hoping to keep it there.

Also just tested my new TM Pro water mix and it came out to be 7.5-8 @ 1.025 (Elos test kit). I'll add some buffer to get it to 9 before my next water change on Saturday. That's a good call and not something I had done previously. Will make it part of the regimen.

As far as my PO4 goes, I stirred up some stuff the day before I tested which most likely caused a spike. I retested today and it came out to be .07. It's coming down. I may actually add some new GFO to pull that down. It needs to be replaced anyway unless you think that's a bad idea at this point.