Help! Stn , rtn

[RobbieMVFC]

Hi all , I am reaching out for help .
I have had my tank running for about 3 years now and its a SPS dominated Tank.
the last 4/5 months I have STN come and go .
It all started about 5 months ago .
I had an Alk swing from 6.5 to about 8.5 when I was dialling in a new dosing pump.
a week later RTN started on 2 corals then STN started on a few more.
after losing the majority of my SPS . I waited for things to settle down (4/5 weeks) I started stocking again .
because my p04 was at .30 so I started doing a 15-20% water change every week. I also reduce feeding to every other day.
so now STN has started again.
In a panic and not to endure it all again I ripped out my Bio-pellet reactor.
thinking that it maybe making my water to sterile.

the setup..
3x2x2 tank
lighting LED zetlight 360pro & 3x39w T5 . soon to switch back to all T5's 6or8 depending on $$$$$
1 actinic , 1 purple plus & 18k
Skimmer skimz 161
Tunze controller with 2x 6055 & 1 6095.
RO bio pellet reactor (removed 2 days ago)
test are
ALk 7.6 Steady for the last 4 months
Cal 450
Mag 1240
Ph 8.1
Nitrate 0
Po4 since removing reactor back up from 0.10 to 0.25
RODI used TDS 0 p04 0.00.

Also now getting green algae on the sand bed .I am scared it maybe a cycle.
maybe it is also related to flow . I have redirected flow to that area.

Have I done the right thing removing the bio-pellet reactor ?
I am also going make a section in the sump as a small fuge in the sump.

 

[hedgedrew]

What salt you using for all water changes? That's lot of po4 swings also. That will kill them too. And now you may be loosing bacteria from bio pellets. You may need to supplement with some vodka vinegar now but I think I would target. 10 po4. With small gfo or something. Without anything your levels may swing. Phosphate changes up or down just as bad as alk swings. I'd rather see some nitrate like 3 to 5 with lower overall po4. But stable is the key. Stripping water too fast ain't good either.

 

[hedgedrew]

I know I didn't give you simple solutions. But just some guide on how stable it needs to be. Gfo is tough also cause you will be going dn fast and can cause damage. But once down, then it's easy to maintain stability with small gfo changes every few weeks maximum. Btw gfo cycles suck also.

 

[Ross33]

How old are your RO membranes and do you know what your TDS is?

 

[RobbieMVFC]

Thanks guys. I replaced all the filters about 4 weeks ago , before that it was about a year ago. TDS reading is 0 , po4 out of the filters is 0.00
I use Red sea salt ( the blue bucket)
I have just replace my titanium heater with a glass one.
also getting a grounding probe to try that .
the P04 swings not sure what to to there
I am starting to think big and often water changes are not the answer .
or should I ?

 

[hedgedrew]

I will often see some stn after big water changes. I have found that 15 per is about it. But again I think it's about change. If new water you put in has 0 nutrients and you have ezxcess po4 in tank I guess we bringing it down and changing things. Water changes I guess can help if it's an imbalance trace element thing. But if it's not, probably can also do damage. I think sanjays speach last year at macna said that doing nothing and waiting it out to stablize was just as good if not better course than massive changes and reacting too much too fast. That's salt is fine and won't pop your alk from water changes also.

 

[hedgedrew]

That's salt is fine and is mot causing alk spikes but sometimes too much change causes more stress including big water changes. Unless it's an imbalance or trace element issue I'm not sure large changes do much at all except bring down nutrient levels in mathemetatical dilution. Sanjay gave a speech last year at macna that said we often react too far and too fast to stn and doing nothing is a viable alternative that worked just as well

 

[Panta rhei]

Something that is not related to parameters is metal pollution. Double check for any iron, copper, brass metal part that can be in contact or near the water.
Have a friend with rust dirpping during the night from tangential fans, another one with a iron bolt locking two tube holders.

 

[RobbieMVFC]

you maybe right , l also have a frag tank that I neglect. All I do is a 20% wc once a month.
all I have on it is a cheep skimmer and some leds lighting, a cheep wave maker and that's it.
Its full of Acros and they are all doing great.
all I do with it is top up the water level with RODI water.
I don't even check the parameters ,apart from Salinity.
..
how do you check for metal pollution?
I have heard about it hence why I removed the titanium heater but I have no idea how to test for it
also can you use a normal multi meter to check for voltage leaks?

 

[PaleHorse]

you maybe right , l also have a frag tank that I neglect. I don't even check the parameters ,apart from Salinity.

I used to be like you until i realize how much better my corals can be. i would often get asked what my parameters were and i didnt even know what that was!!! That was when i had "LPS" Havent said that in awhile.... those were the "dark" ages for me lol.

Anyway just stabilize parameters and dont do anything to drastic. :bounce3:

 

[Panta rhei]

You can use cuprisorb from seachem or the poly filter pads.
Also ime one change at a time and some time between changes are keys to stability

 

[RobbieMVFC]

thank you guys , I will buy some cuprisorb and drop down to a 5% water change once a week.
I have also added a refuge (only algae ) in my sump.
I decided (with your help ) to do the hardest thing of all ....nothing , I hope everything will settle down , Last time I got STN about 2 months ago . I panicked and did heaps of water changes stripped everything and cleaned it but it didn't help.

wish me luck .

 

[Panta rhei]

Good luck and keep us posted!

 

[RobbieMVFC]

Hi All , just a quick update . I have not lost any other SPS corals since my last report.
One thing I have noticed is my Monti's, Birdsnets frags and LPS all look to be doing significantly better.
This is one week after removing the Bio-pellets.
Most the Acro's haven't made a full recovery but that's to be expected considering its only been a week.
All parameters have been stable including the 0.25 phosphate's....
Last night I did a 5% WC.