Is EI dosing right for me?

[ChrisMachell]

Hi all, looking for some advice on the best kind of dosing for my tank. I have a 240l, CO2 injection (in line diffusion). I have been dosing with TNC Complete, usually 20ml after a water change (twice weekly), occasionally supplemented with root tabs in clay substrate. Lights are fairly low (the Fluval LED strip that came with the tank) on for approx 9 hours a day. Fish stock is 9 black ruby barbs, 6 boesmani rainbows, 4 mollies, 7 sterbai cories, 3 sodalis cories, 2 apistogramma, one clown pleco and 3 nerite snails. Typically do two pwc per week, totalling 50% water change weekly. Have been running this set up since Christmas.

I would consider the tank to be moderately planted, growth has been good and I'm largely really happy with my modest achievement. However, lately I've noticed some plants (especially hygrophila polysperma) shedding a lot of leaves (five to seven a day), often with holes which I believe indicates a potassium deficiency. My nitrates are always around 20ppm due to our tap water, so I have been considering swapping to EI dosing, skipping on the nitrates and focussing on the other macro / micro nutrients. Is this suitable for my kind of set up or would I be better sticking with liquid ferts and just upping the dose?

Any advice greatly appreciated!

 

[X3NiTH]

Do whatever is easiest for you. It’s probably not likely to be a K deficiency you’re going to at least have between 2-5ppm coming from the tap source, low but not deficient.

Issue is probably down to flow and distribution of CO2 around the tank, place your dropchecker near where you have an issue and see if there is a difference to where it is normally located.

 

[ChrisMachell]

Do whatever is easiest for you. It’s probably not likely to be a K deficiency you’re going to at least have between 2-5ppm coming from the tap source, low but not deficient.

Issue is probably down to flow and distribution of CO2 around the tank, place your dropchecker near where you have an issue and see if there is a difference to where it is normally located.

Thanks, I'll give that a try! To be honest I'd like to avoid EI if I can. I don't need my tank to be world class, happy fish and plants are good enough for me

 

[Zeus.]

As X3NiTH said the chances of it being K are very unlikely. 95% of problems with CO2 injected tanks are down to fluctuating CO2 levels during the photoperiod and most of the reasons for the fluctuating CO2 levels are inadequate flow in tank or poor CO2 on/off timings and the main symptom is holes in leaves which leads to leaf loss and internodal elongation in stem plants.
A pH profile will help sort your CO2 timings out, but flow is 'KING' the CO2 injected tank.
What filters/filter outputs are you using and any powerheads

 

[ceg4048]

I've noticed some plants (especially hygrophila polysperma) shedding a lot of leaves

Typical indication of poor CO2.

often with holes

Holes in plants, if not caused by predation, is only ever caused by poor CO2.

I have been considering swapping to EI dosing, skipping on the nitrates

Terrible idea as Nitrogen is the second most important nutrient, second only to Carbon.

Cheers,

 

[Andy Pierce]

Hygrophila polysperma grows just fine with no supplemental CO2 whatsoever, so you've got some other problem going on (in addition to the CO2 problems). With supplemental CO2 the Hygrophila should just grow all rampantly out of control. If you do decide to try EI (for cost reasons if for nothing else) I wouldn't try to overthink it by messing with the default EI parameters and specifically not to reduce any key components (N/P/K) to "compensate" for what may or may not be coming through in the tap water.

With the clay substrate, are the plants able to form any kind of meanful root structure at all?