[Mr. Cardholder]

So I have a 75 gallon heavily planted tank. FX6 canister, two Finnex Ray II lights, 10lb CO2 tank with a MC122 pH controller. 4 hour photoperiod.
pH is 7.3
GH is 0-2 drops
KH is off the charts around 22-25 drops
0 Ammonia, Nitrites, Copper
Maybe 20ppm Nitrates
I keep my CO2 at 30ppm
I dose KNO3 and KH2PO4 only, every other day.
Current stock:
11 White Tip/Candy Cane Tetras
5 Enormous Cories of some kind
2 Scarlet Kribs
African Leaf (three inches maybe)
Some amount of Otos
3 Horseface Loaches
Farowella Cat
Bristlenose Pleco
So my problems start at the acclimation process. I drip acclimate everything that goes in, but certain fish have a huge problem going in while others don't. The fish currently in the tank are very active. In the past I've added Marbled Hatchets that all died off one by one over the course of a week or so, ghost shrimp that all die in a couple days, same with cherries, knight goby, rummynose tetras, knife fish (jumped out, twice), gold nugget pleco, and emperor pleco. Now the plecos lasted a couple weeks before kicking the bucket, but it is inevitable. I can only assume that it is the CO2, but backing off on the concentration means an explosion of BBA which leads to the next problem.
I've had this CO2 system for a while now, but only recently got the controller (week ago). I got it because I leave it on 24/7 and have had nothing but constant trouble with Black Beard Algae. I figured it was because the concentration went up at night when the CO2 was not being used by plants. I have it calibrated and set to turn on when the pH is above 7.1 since that was the reading at 30ppm of CO2. My tap water is 7.7. So far the pH has only risen beyond 7.1 to 7.3 now, the monitor has never turned off the solenoid on my rig, and I have not adjusted the CO2 output.
What is going on?

 

[BobLsaget]

I'm no expert but 4 hour photo-period sounds really low. BBA is caused by flucuating/low levels of CO2. I would work with that CO2 regulator as well to get that adjusted. I'm no expert but I would concentrate on those things.

 

[truvader]

4 hour photo period does seem really low to me. Personally I would run the co2 solenoid off a timer until you get things kind of dialed in. I would suggest starting with a 7 hour photo period with the co2 coming on 1 hour before the lights and shutting off 1 hour before lights out. How are you measuring co2? With co2 running as much as it is with a 4 hour photo period you may very well be gassing your fish.

 

[Diana]

Fish are acclimated to the mineral levels of the water they are in.
If that water is harder or softer than your tank water they cannot deal with that change over just a few hours acclimation.

Here is how I do this:
1) Set up a quarantine tank with low GH, KH, TDS.
2) Test the water in the bag when I buy new fish. GH, TDS, KH are the important ones. pH is less important. It might be odd anyway because of the fish respiring in the bag, raising the CO2 level.
3) Make the Q-tank match that water. GH, TDS, KH. Never mind the pH.
4) Drip acclimate the more sensitive fish.
5) Over a period of about a month I do water changes that gradually alter the mineral levels until they match the main tank. At the same time I am monitoring the fish, medication for parasites or diseases.

 

[lauraleellbp]

Livestock also should be slowly acclimated to elevated CO2 levels.

At this point, I'd take care of your algae isses and get a drop checker with a calibrated 4dkh solution inside to get a more accurate CO2 reading than just guesstimating based on pH (since there are so many other variables that can affect pH besides just CO2).

Once you've gotten the CO2 and plant/Algae issues stabilized, back down on both your light and CO2 levels for a few days any time you add new livestock. You can use the QT proceedure Diana just outlined to acclimate new livestock to your hard water, then after they're through that process, get them used to higher CO2 than they're likely to have ever been exposed to.

Keep in mind that all changes are stressful on livestock. Patience on your end will be one of the best things you can do to improve their chances of survivng all these transitions.

 

[Mr. Cardholder]

I use a drop checker at keep it at a nice lime green, so I know that the CO2 concentration isn't too high. I have no way of lowering the light by anything but half (removing one light entirely), would that be too low? I don't have any other algae issues, just BBA.

 

[lauraleellbp]

I wouldn't run 1 fixture indefinitely, but lowering the light level just for a week shouldn't harm your plants, and would allow you to lower your CO2 for the introduction of new livestock.

 

[adive]

Without knowing the OP's experience with planted tanks: I would not suggest a newcomer dive into a big hi tech CO2 injected tank at the outset. Give it time - maybe as much as 6 months or more to learn various things, experiment on smaller scale until you get the hang of things. Start with a low tech tank, maybe with no co2 injection, gradually start ramping up things as in light, co2, ferts, etc as you start understanding how it works. Keep tonnes of plants and understock the fish.

Just my 2c from my experience with 2 successful very low tech tanks, no co2, no Excel/glut. Goodluck.

 

[brandon429]

for only 40 bucks so many problems can be solved, simple solenoid on off co2 switch hooked to 15$ radioshack wall plug timer. I figure if you are this far in, why recess just buy the right triggers. 24x7 co2 sounds like your culprit, just regulate it cheaply, I did, worked for 15 yrs.

 

[MamaJu]

I feel your pain. I have the same luck with fish in my 75 gallon. I hope things get better for you.

 

[BobLsaget]

Just to mention, this has worked for me in the Past use Hydrogen peroxide as a temporary fix. Just put a 3% solution in a spray bottle and spray the algae while its underwater, this is best done before/ during a water change before you add the water, with the lights on. I have several types of plants in my tank including Moss and Marimo balls, did not damage any of them, but sure made the Algae wilt after a few days.

Please keep in mind this is a temporary fix and this will not solve the Imbalance problems you are having with your water chemistry/lighting schedule, your concentration should be kept on that.