Dosing questions once again.

[hashbaz]

I bet most of you are tired of the inexhaustible onslaught of dosing questions – but I am starting my first high light tank and would prefer not to describe the experience as “growing algae and learning the hard way.” So I hope 1 or 2 of you may be willing to beat this dead horse a little more.

I have spent innumerable hours dreaming, researching and planning, and now that I have a job, I can finally afford my dream tank. I know every tank is different and has different requirements, but I would appreciate a few suggestions.

Equipment:
75 gal tank
220W CF (3wpg)
Pressurized CO2 with Ph controller
9 bags of EcoComplete

Anticipated Flora:
Lots of fast-growing stem plants

Tap water:
Cold water: GH 200ppm
Hot water: GH 0 ppm and 160 ppm K (I have KCl in the water softener)
Warm water (77F): GH=140ppm and K=50ppm

Anticipated dosing schedule:

SAT:
50% water change
Add 25ppm K (from tap water)
Add 10 ppm NO3 (from Ca(NO3)2 )
Add 1 ppm PO4 (from KH2PO4)

SUN:
Add enough CSM+B to add .1ppm Fe

MON & WED:
Add 5ppm NO3
Add .5ppm PO4

TUE & THU add enough CSM+B to add .05ppm Fe

FRI: Spend a little time with my wife instead of the aquarium

I assumed that with my hard water and large water changes, I will not need to add Ca or Mg. Is this a good guess?

How fast is K absorbed? Should I be OK dosing 25ppm once a week?

I can measure PO4 and NO3 and adjust accordingly, but for Iron/Traces is it best to keep just enough that my plants do not show deficiencies, or should I add a little more than “just enough?”

I am also curious about first starting out. My plan has been to jump in all at once – move the fish and filter media from my 29g, add lights, plants, ferts all at the same time. Or is it better to gradually increase the light and/or fertilizers? I recently read a suggestion not to fertilize for the first 3 weeks – but high light and no ferts seems like a recipe for algae.

Thanks for you help and for reading my long, dreary, tiresome post.

 

[czcz]

It's a very good schedule and set-up. I think you're cutting dosing a little close, and suggest dosing on the high side with your light, like 1.5-2ppm PO4 and 15-20ppm NO3, then once you feel confident about predicting uptake, cutting it closer if you want to drop N to get color or something. Interested in reading what you think of Ca(NO3)2. That light should grow anything you want

I assumed that with my hard water and large water changes, I will not need to add Ca or Mg. Is this a good guess?

yes.

How fast is K absorbed? Should I be OK dosing 25ppm once a week?

I'm not sure of K uptake rates, but you can definitely dose it once a week. If you get a little more than your target you should still be fine.

I can measure PO4 and NO3 and adjust accordingly, but for Iron/Traces is it best to keep just enough that my plants do not show deficiencies, or should I add a little more than “just enough?”

Using plants as indicators is the best (and maybe only effective) way to figure out trace levels. Fe levels are debatable and is something you should experiment with, so let me give you all the sides I am aware of. Lots of people dose Fe somewhat high (.2-.3ppm) because they find it gets great color. Walstad suggests too much Fe induces algae. Barr says he doesn't think high Fe induces algae, and that the benefits of high Fe are no different than high traces, and observes no fish stress or induced algae even at 1ppm Fe. IIRC, Travis maxes at .2ppm Fe and of course gets amazing color from his plants.

FWIW, I prefer .3ppm Fe under similar light to your tank (using lumens/sq in) and find better color from my plants than I do at .2ppm Fe or less. I would suggest starting at .2ppm Fe to assure no deficiency, and because its easy to increase or decrease dosing by 50% should observation warrant it.

I am also curious about first starting out. My plan has been to jump in all at once – move the fish and filter media from my 29g, add lights, plants, ferts all at the same time. Or is it better to gradually increase the light and/or fertilizers? I recently read a suggestion not to fertilize for the first 3 weeks – but high light and no ferts seems like a recipe for algae.

Agree -- definitely start dosing and CO2 immediately, along with high initial plant mass. With plenty of fast growers, you'll have a great chance at defeating algae, and they'll double as nutrient indicators.

Good luck and hope this helps, hashbaz. Look forward to your tank!

 

[hashbaz]

That was a very comprehensive (and helpful) answer, czcz. Thanks!

Interested in reading what you think of Ca(NO3)2.

My original plan was to go with KNO3 but I worried that with 50ppm K in my tap water that I might get a little too much K in my water.

Are there any issues to watch for when using Ca(NO3)2? I was glad to see that it actually cost a little less.

 

[czcz]

Glad to help I've no experience with Ca(NO3)2 but have been eyeing it for awhile too. I'm especially curious about how well it dissolves.

 

[newfound77951]

I would definitely start dosing right from the start...I had read in a couple of places not to dose for the first few weeks after set-up, so that's what I did....was OK for a week and then the algae grew so fast I swear you could watch it grow. That's at 4 wpg. Once I started dosing and added a variety of algae-eating fish I got everything under control pretty quickly. I went from no algae to algae forest to (almost) no algae again in 4 weeks!

 

[Glenc]

Thanks czcz and hashbaz. Great question and answer. I am still experimenting with my fert regime and have alot to learn, pretty good results so far, but still having a few problems. Just learned alot from both of you.

 

[7Enigma]

I don't know what your fish stock is from the previous tank but I'd get a handful (5-10) Otocinclus catfish. These little buggers are amazing at cleaning algae without damaging the plants and are very fun to watch as they will school and play. You could probably get 20 and still not have a problem, but might need to suppliment with algae wafers (which mine love) and fresh veggies.

BTW I have 4 Oto's in my 20 gallon, and they do a great job of keeping the algae almost non-existent (at ~5wpg with DIY CO2). Always have chubby bellies so you know they are eating lots of algae.