Time to ask for help

[Reefmaster]

ok, this *^&#$ reactor has me puzzled. i know there are some out there who entirely understand the chemistry involved and if i had time i might look into it, but i don't, so i'm looking for the idiots guide to tuning a reactor.

details
precision marine 622 (the big beast) on a mod stocked 135g (total volume 200g)
co2 - 50 to 60 bbm
effluent - 50 ml/min, ph - 6.5
alk usually about 3.0 meql
calcium levels high, 480-500 (not yet precipitating)
tank ph ranges from 7.6 or 7.7 to 7.9

have been dosing kent pro buffer dkh but this is b.s. the reactor should be looking after alk too. using a.r.m. media.

all the corals are doing ok, but not getting the sps growth that i hear others are getting. lighting is 3x400W and all other param's are good.

i would like the stupid steps to get the alk and ph up on this system cuz its clear i'm not getting it on my own. thanks all. shane

[SuperFudge]

Hiya Shane,

You could probably bump the co2 to 1/3 again what you are currently at...dont worry,ph wont drop anymore and stay at your current effluent rate.
Then,once a higher alk is achieved(less than a week probably)increase both simultaneously(sp?) to meet ca and alk consumption.

This will raise your alk and drop calcium abit in the beginning,but its ok....you should get good noticeable growth with a ca of even as low as 390/400 and just worrying more about a good alk @ 3.8+.

You shouldnt need to use buffers at all,just keep bumpin the co2 up! :D

Keep us posted,Marc.

[ 23 March 2002, 20:25: Message edited by: Superfudge ]

[DJ88]

Hey Shane,

Long time no see. smile.gif

I'd follow what superfreak, err superfudge said. :D

Bump your C02 up to say 80 to start. And go from there.

More of a concern to me towards tank params is the tank's pH. I run mine at 8.2-8.3. You will want to boost that With your effluent at only 50ml per min your reactor isn't keeping the tank pH this low. Are all three stable(alk, pH and Ca)? You are going to have to drop the Ca a bit in the tank IMO so that the pH will climb back up and then the alk will level out a bit higher. Try running a bit higher BPM then slowly increase the effluent rate. I am running about 80 m per min on my 33 with a pH of 6.8. I'll get you the alk of the effluent if ya want to give you and idea. Tank alk is 12-12.5, Ca 450 and pH of ~8.3. All three are stable.

To paraphrase all that gobbledegook.

Your Ca is high, pH is low. alk is ok. You are going to need to get Ca down, pH up and alk will follow. To do this I would say increase the BPM as well increase your effluent rate. Give it a few days between changes to see what kind of effect it has. Do one at a time. BPM then effluent.

If you still didn't understand(I barely do) :D , post away..

LOL

Keep us posted. smile.gif

[ 23 March 2002, 20:48: Message edited by: DJ88 ]

[Canadian]

There really should be no need to run Caribsea ARM at pH 6.5. You should be able to get acceptable parameters in the pH 6.8-7.0 range with ARM.

Are you dosing anything that has Magnesium in it? An imbalance of magnesium can allow your Ca to climb out of range in relation to your Alk. With such a high Ca concentration your lowish Alk readings aren't really very surprising.

And I agree with Marc that Ca in excess of 400 mg/L or so really isn't necessary. Good Alk levels will help ensure your SPS get good growth rates - Marc has very impressive SPS growth rates so I'd be inclined to take his advice (which also coincides with Darren's).

I'd also look into other possible causes for your low pH. I'm sure you've done this already, but make sure your surface agitation is adequate to promote good gas exchange, and it's also possible that, with the cold weather we're having, you've had your windows closed and there may be a lack of good gas exchange in the room your tank is in, leading to higher room CO2 and lower O2 levels. Do you have a fireplace or woodstove in your house that you've been using during this cold snap?

[ 24 March 2002, 21:09: Message edited by: Canadian ]

[Aquattro]

Shane, what are you NO3 levels? Nitrate can neutralize alkalinity and affect pH. Just a thought...

[Reefmaster]

thanks for the replies guys.
although i'm no dummy i feel a bit like one which is why i've asked for the stupid steps because i've tried a lot of variations already. i know i want the calcium lower but i haven't yet figured out just how one goes about lowering the calcium levels if they can't raise the alk. ok - comments.
marc - i thought what you suggested was what was needed, but since i dialed up the co2 the pH is struggling to hold at 8.8 (ed. wooooaaah, 7.8! ooops, damn surgery!) in the evening. am sticking to my guns on your advise.
darren - ya the three are pretty stable, and i know the ca is suppressing the alk which in turn suppresses the pH, but trying to heal those that are suppressed is tough.
andrew - i spoke with mike at pm and he said those running the arm should get away with 7.0! what the heck is wrong with my setup?!? no, no dosing magnesium. have considered trying to see if that helps, but don't have a mg test kit. gas exchange on the surface is very good - i think those who have seen my system have commented on the surface area and oxygenation i get from two 40g top/bottom sumps located remotely from the tank. now the sumps are in the furnace room so whether you've touched on something there or not... hmm.
brad - nitrate is almost always undetectable, sometimes a faint trace, never since the tank was moved has it reached 5 ppm. although i don't even test that anymore, i will check tonight or tomorrow to confirm. interesting though.

to summarize, presently
60 ml effluent, 6.3 ph
7.6 to 7.8 tank ph
alk 3.4 meql
ca 500

thanks again, and any feedback is welcome. shane

[ 25 March 2002, 22:31: Message edited by: Reefmaster ]

[DJ88]

Shane,

I hope we can help ya out.. That tank pH is unbelievable. :eek:

Something is obviously keeping the rest of the system out of whack. man I wish I was a chemist.

Speaking of which have you tried talking to randy holmes farley? On RC? I think you may need to.

I'd suggest dosing kalk to try n drop the pH but you have such a big tank you'd need to dose way too much.

I just re-read your posts Shane. Noticed your alk is up a touch. which is good. small victories right? but your pH has changed by a full point in the two posts. Is your tank pH 8.8? or 7.8? 7.8 right? I hope so. smile.gif

[ 25 March 2002, 21:21: Message edited by: DJ88 ]

[Reefmaster]

lol, ya 7.8! thanks darren.

[Silverfish]

Hi Shane, just a thought on the furnace thing, ;) the one you have in there has exposed burners which burn air from in the room. I did not look to see if you had adaquate fresh air supply to the room, but I would suggest a 4" fresh air hood run straight into the room. Maybe even a 5" if you don't have much fresh air into the system already.

I can hook ya up if needed. smile.gif

[DJ88]

Hey! there is something to look into Shane. If your room is low in O2 I am under the impression that your pH will be depressed due to higher levels of CO2. but once again. I am not chemist and could be waaaay wrong..

[Reefmaster]

well, its certainly possible this is the culprit. bruce, does this simply involve punching a hole through an exterior wall, or is there some sort of mods to the furnace. either way, i should probably do it i think to eliminate the possibility.
shane

[Silverfish]

Yup, just cut a hole in an exterior wall and shove a fresh air hood through. That's it!

There are also cool air traps that can be used as well to keep air from pouring in and causing a nusiance.

Gimme a call for info