Can high kH cause algae problems with EI dosing

[Jeff1192]

I have started up a pressurized CO2 system on my 90 gallon. I'm still trying to sort out some algae problems (mostly BBA and some hair algae). I've cut back my lighting to 9 hours a day and I'm only dosing 2x a week for macros and 2x a week micros. My kH is really high (12), could this be causing a problem for nutrient uptake for the plants? I just want to rule this out as a possible problem. I think most of the BBA was from fluctuating CO2 levels as I have been tweeking the levels lately.

At each dose, using dry ferts directly dosed in water, I'm adding 3/4tsp Nitrates, 3/16tsp phosphates, 1/4tsp potassium and for micros it's 1/4tsp micros. I slowly built up dosing to 6x / week with 12hrs of light but started to get a lot of BBA and hair algae. I cut light back to about 9hrs a day and dosing to 2x week for micro and macro.

Also should my pH continuously drop throughout the day? My CO2 turns off just before lights out and back on a few hours before lights on. By the time my lights come on my pH is around 7 but by the end of the day it has slowly dropped to about 6.85. I haven't been relying on the pH/kH table to determine my CO2 because of my high kH. Instead I have been using the 24hr testing of a sample of tank water (remove some water at lights out, test it, then measure the pH in that same water 24hrs later). With this method my pH rises about 1.6 degrees.

Thanks,

Jeff

 

[VaughnH]

If you make or buy a drop checker you will have a much better idea whether or not you have enough CO2 injection. How do you inject it - external reactor, ceramic difuser disc, etc? And, do you have good water circulation in the tank?

Even 9 hours is more than necessary for a photoperiod. I have been using 8 hours for some time now, and the plants grow fine. I suggest you reduce yours to no more than 8 hours and maybe even less.

As far as KH goes, I have never heard or read that it will affect algae growth.

 

[rich815]

If you make or buy a drop checker you will have a much better idea whether or not you have enough CO2 injection. How do you inject it - external reactor, ceramic difuser disc, etc? And, do you have good water circulation in the tank?

Even 9 hours is more than necessary for a photoperiod. I have been using 8 hours for some time now, and the plants grow fine. I suggest you reduce yours to no more than 8 hours and maybe even less.

As far as KH goes, I have never heard or read that it will affect algae growth.

I would agree with all that.

And make sure your water circulation is good and strong for proper and complete CO2 dispersement. Pulling back your fert dosing to 2x a week is not a good idea as it will only make your plants less able to compete against the algae and may actually cause more algae as a result. I used to be 10-12 hours of light but got GSA in a big way. Dropped off one of my 4x54W T5's on my 72 gal and my photoperiod to 8 hours and my plants still all grow fine but the GSA and BBA have become much more manageable.

I follow your dosing amounts but for my 72 gal, how big is your plant biomass?

 

[Jeff1192]

My water circulation is good. I have 2 eheim canister filters ( a Pro II and a 2215) and the diffusion is an external reactor hooked up to an Eheim Pro II. I get complete absorption of the CO2 (I never see any bubbles coming out the spary bar). If that's not enough circulation would a powerhead help move things around. I don't know how to describe my plant biomass but I think it's pretty heavy. I've seen much more densley planted tanks than mine but I do have quite a few plants in there I guess med-high plant biomass would be the best way to describe it.

If you follow the same dosing in your 72 gallon would you increase the dosing in my 90? If so by how much. I was thinking that my phosphate dosing might be a little low and figured I'd up it to 4/16.

What do you guys think.

Thanks

Jeff

 

[rich815]

My water circulation is good. I have 2 eheim canister filters ( a Pro II and a 2215) and the diffusion is an external reactor hooked up to an Eheim Pro II. I get complete absorption of the CO2 (I never see any bubbles coming out the spary bar). If that's not enough circulation would a powerhead help move things around. I don't know how to describe my plant biomass but I think it's pretty heavy. I've seen much more densley planted tanks than mine but I do have quite a few plants in there I guess med-high plant biomass would be the best way to describe it.

If you follow the same dosing in your 72 gallon would you increase the dosing in my 90? If so by how much. I was thinking that my phosphate dosing might be a little low and figured I'd up it to 4/16.

What do you guys think.

Thanks

Jeff

Well, I'd definitely go back to the 3x a week on alternate days of the micros and macros for sure. Maybe increase the dosing by 1/8 t. across the board? Perhaps get a few more plants in, something good and fast growing like some hygro stems or myrio get some stronger plant biomass going (maybe you can post a digicam snap of your tank?). What's you GH? Are you dosing anything like GH booster (assuming it might be needed)?

I have an Eheim 2026 and 2028 going on my 72 gal with an external DIY PVC type CO reactor on the output line of the 2026. Sounds similar to what you got going. Even with that though until I got a Koralia 2 going in the tank too I was having small BBA showing up from time to time, likely because of "dead spots" of not enough CO2 circulating around. So you might consider a Koralia 2 or even a 3 (though I did have a 3 and found it too strong for my 72 gal).

 

[Jeff1192]

I'll try to post a picture later tonight if I get a chance. I actually have a uv sterilizer that I was going to hook up to my tank either using an Eheim aquaball powerhead that I'm not using right now or in-line with my other canister filter. Maybe I'll go the powerhead route now to get better circulation. I have never actually tested the gH of my water maybe I better pick up a test kit.

On a side note I though BBA turned up in more high flow areas of the tank (that's where most of mine is).

Do you think I should stick with the 9 hour photo period or should I go back to 12?

Thanks

Jeff

 

[aquabillpers]

. . . If so by how much. I was thinking that my phosphate dosing might be a little low and figured I'd up it to 4/16. . .

If you are concerned about the phosphate level, why not buy a phosphate test kit? Seachem has a good one, and it includes calibration fluid. Then you wouldn't have to guess.

Bill

 

[Jeff1192]

Ok so I did some tests:

-my gH is 12
-my phosphates show the darkest colour on the card which is 10 so they might be higher than that it's hard to say (I'm not a big fan of those tests)

I've also attached a photo. In the middle of the tank where you can see the black background I have about 10 stems of limnophila aromatica planted. I had to trim the tops off and throw out the bottoms because it was full of BBA so I'm waiting for that spot to fill in.


Jeff

 

[VaughnH]

That is a very nice looking aquascape, but it is very full of plant mass, so getting adequate water circulation is going to be very difficult. You can't establish a circular flow pattern, because the plants will kill it less than half way around the tank. If you use a couple of powerheads, preferably Koralia type powerheads, you should be able to point them so virtually all areas are getting some water flow. Without that many areas will be starved for CO2.

 

[Jeff1192]

What I'm confused about though is that almost all the BBA in the tank is on that large piece of driftwood which is one of the highest flow areas in the tank.

Jeff

 

[Tom Barr]

Examples of high KH and dosing EI:

Answers the question, KH is 11, Gh is 24.
Even without high plant biomass(pretty sparse planting)

Regards,
Tom Barr

 

[Jeff1192]

Excellent so that definitely rules out my concerns about high kH. Any ideas what the problem could be based on my dosing. Could it be a circulation issue?

My lighting on the tank is 4 x 54watt T5ho lights. They were on for about 12hrs a day prior to the algae out break and I turned them back to about 9hrs a day now.

Like I said in a previous post....I had been fiddling with my CO2 levels for a little while before the outbreak as well so it might have something to do with that.

Thanks,

Jeff