Junior Poster
Apr 13, 2007
I have an interesting quandry. I have a 65G tank, and it needs a de-stocking. The 2 severum and one festivum like to eat plants like noone else's business. I feed the tank a head of romained a week to try and keep the fish from my swords.

The tank was fine until the fish realized they lived in the buffet and started eating everything. There was a fish induced plant crash. That came with an infestation of BBA.

I've since added a Siamese Algae Eater and cleaned most of the stuff out. Trimmed most of the leaves. The CO2 was off for this time. Even with the CO2 off, I'd notice most of the fish floating at the top of the tank as if the remaining plants and fish had used up the O2 in the tank and were looking for more. I added an airstone and things were fine.

Fast forward a couple of months. I try to rehab the tank. Add some more sword plants, replenish the CO2. I move the airstone to a timer so that it turns on 1/2 hour after the lights (and CO2) turn off, and turns off 1/2 hour before the lights come on.

The tank is a 65G with 3x96w (2 10K, 1 6.7K) bulbs, a CO2 tank with Milwaukee controller. The PH is set for 6.3, and it rises overnight to 6.7 with the airstone, then begins to drop when the lights go back on.

With the fish being Nitrate factories, and making a big mess, eating all that lettuce, I've started doing 50% water changes weekly. That led to me thinking "I'll try that EI method..."

Rambling intro over, I've read here that you want that CO2 as stable as possible, and that is the biggest key to stopping the issues.

With the 50% water changes weekly for the last couple of months, my nitrates are at around 40ppm, phosphates are at 2.0, and carbonate hardiness is 3dgh. (Non-calibrated dropper based kits).

Those parameters are in-line. Today I was thinking "I must be missing traces, if those seem to be in order, due to fish pooping", but now I am wondering if the problem is my CO2 levels "bouncing" daily.

How would you recommend I go about balancing that out? Turn off the air stone, and point the spray bar up to create ripples only? I am thinking that with my fishes adding to the nitrate problem, I'd start dosing EI as if I have a 40G tank, and see how that works out for me.

(and thanks for the awesome guide, and help with it, Greg).

Thanks for the info,



Guru Class Expert
Jan 12, 2007
Dorset, UK
have you got a water report to check to see if you have nitrates in it? its very likely you have, at one point my tap water had 30ppm NO3 in it before it even hit that tank.

As far as CO2 is concerned, make sure your not adding it at night, and that you have good surface movement 24/7.. thats extremely important. Gasping fish isnt caused by CO2, its caused by lack of O2.. adding CO2 wont deminish O2 but it will lower the fishes tollerences to it.

For dosing, follow the link in my sig for the nutrient calc, that way you can dose for the correct size tank, but if your adding tap water, get a water report to check whats going in and adjust your dosing accordingly.

I would get hold of some Tropica Nutrition for your traces, add that on the EI off days and youll be all set id say. Fish arent going to produce anything you want really other than Nitrates via nitrification and even then, not enough of that either. With you tank flourishing, youll be amazed at just how much the biomass will absorb.


Junior Poster
Apr 13, 2007
Just doing a home test, it appears that the nitrates are at 10ppm coming out of the tap. I tested last summer and it was more like 40ppm coming from the tap. I don't know if they've made improvements, or if it's just the cold reducing the amount of nitrates in solution.

With regards to the CO2, I pointed my spray bar up, so that the water jetting from the holes end up making little bumps up in the water (no splash) and left it like that overnite. I disconnected the timer connected to the air stone, and this morning the fish weren't glommed to the top of the tank. That's good news. I'll leave it like that. Also, the CO2 selenoid has been on the timer for the first set of lights that come on/last set of lights that turn off.

I did follow the link for the dosing calculator, it's great! For the Trace I have the CSM+B Plantex from Greg Watson. Should I be using the Tropica Nutrition instead, or in addition to?

And yes, I was amazed at the amount of nutrients sucked down by the plants. The tank was full and healthy, with fast growing plants. Heck, the reason I came here is that I am getting frustrated with having the biomass I do have and not having it suck down nutrients like it should be.

Also, are swords just slow growers? I have mostly Melon and Radican Swords, with a bit of Wendtii and coffeiola. It seems to be what I can keep and not get eaten before the romaine. Any other recommendations of less savory plants?



p.s. I saw some nice CO2 dropper tester thingys, I may need to get one. I just hope someone comes up with a design that can integrate the existing pH controller.