Piet Posted March 29, 2015 Report Share Posted March 29, 2015 Hi all, I've recently upgraded a few things in my 2ft (20 US gal) planted tank to get it towards the "high tech" end of the spectrum. It's running 2x24W T5HO bulbs at 6500K and 10000K along with pressurized CO2 on a solenoid running at about 1.5bps (for the moment) and is filtered by an Eheim 2215 with an inline CO2 reactor. Prior to adding the CO2 I was adding API CO2 booster (excel equivalent) and micro-nutrients, then gave Seachem's NPK a go, though dosing fairly conservatively and dealing with a lot of thread algae during that time. It currently houses 13 rummy-nose tetras, 2 black phantom tetras and 2 juvenile SAEs (smaller than the tetras) as well as 2 riffle shrimp and 15-25 Neocaridina shrimp at a guess. Moderately planted with Blyxa, dwarf hairgrass, a few crypts (wendtii, balanase, parva), Hygrophila difformis, stargrass, pygmy chain swords, and another stem plant species that I can't recall the name of. Since adding the CO2, growth has increased dramatically in the stem plants, but I am still battling with the algae. So much so that I had to severely cut back most of plants to remove the majority of the algae-infested leaves. Ideally I would like to use the Estimated Index for dosing but with Seachem's NPK that will become a money pit unto itself... and sourcing the dry ferts seems rather difficult here, especially KNO3. Regardless, my questions are more about the nutrient balance in a planted aquarium. Quite a few products that are sold as "complete" plant fertilisers specifically state that they are nitrogen and phosphate free, containing mostly potassium, magnesium, sulfur and calcium, and claim that sufficient N and P produced through feeding and fish waste. Is this likely to actually be the case in a high light system? My understanding is that ammonia is the primary driver for most algaes, at least in the spore stage and that plants are more likely to utilise N and P than algae, provided that other parameters are reasonably good for plant growth. Given the relatively high bioload, is it likely that the algae is benefiting from the immediate form of fish waste (ammonia) and then the plants will be struggling to find enough available N and P, hence I would need to supplement them directly with nitrogen? I haven't seen many obvious signs of deficiencies in the plants themselves, just an excess of algae on some leaves and an increase in green spot algae on the glass. Is that also a sign of there not being enough P in the system? If I dose according to Seachem's calculations and ideal nutrient levels I'll be using 100mL of each in under 2 months... but would providing less NPK than recommended contribute more available nutrients to the algae than the plants? Thanks for your feedback - I'm also interested in anyone else's experience with nutrient dosing and higher tech tanks... problems, solutions, stories, etc. Cheers, Piet Link to comment Share on other sites More sharing options...
MCD Posted April 1, 2015 Report Share Posted April 1, 2015 At a first guess.. i would assume you may not be injecting enough co2.. Co2 supposedly drives the uptake of nutrients.. If you are aiming towards a high tech setup then 30 ppm of co2 is good to aim for. If you use this graph you can see what co2 levels you are achieving. Aerate overnight then test ph in the morning to get your base level, then check again throughout the day to see the co2 ppm. Im not saying this will fix all your problems but if you at least know you are injecting an appropriate amount of co2 they you can rule that out and move on to the next thing. The next thing i would check would be that your water is oxygenated enough so that your filter bacteria is healthy and not suffering from hypoxia. If this happens then they are unable to convert your high fish loads waste from ammonia fast enough. Something to bare in mind is that the co2 uptake will change over time as the plants grow and will decrease after a big trim or removal of plants etc etc... I Always aim to have as much plant material actively photosynthesising as i can most of the time. You said you had to cut back a lot of the plants heavily that were infested with algae... if you did this whilst still dosing the same nutrients and co2 then you may have damaged filter bacteria from too much co2 and then fed the algae with the excess nutrients. Im not saying this happened to you because i do not know every detail of your setup but this is exactly what i did with my last setup! lol.. Link to comment Share on other sites More sharing options...
MCD Posted April 1, 2015 Report Share Posted April 1, 2015 Sorry that graph is really small but if you have never seen it then search kh ph co2 chart and you'l find it. Link to comment Share on other sites More sharing options...
vreazz Posted April 1, 2015 Report Share Posted April 1, 2015 Stop the dosing of ferts and co2 leave the lights off for 3 days (your plants will be able to handle that) the algae should be more controllable. Once you have the algae under control i would introduce some ottos or shrimp depending on what other fish you have in the tanks and experment with your ferts and co2 till you get it in the right range kh. I would also play around with the time your lights are on if mine are on longer then 6 hrs i get massive algae out breaks Link to comment Share on other sites More sharing options...
peter m Posted April 1, 2015 Report Share Posted April 1, 2015 One of my tanks(300 lit)has 2 of the old growlux tubes had to stop using api co2 booster and leaf zone as all plants were growing out of control have lights on for about10 hrs day, tank is heavily planted and very well stocked, runs 1200lph canister,800lph internal and 60cms air curtain, when I test water always good do 40% water change 2 weekly. I am still thining out plants each water change. I have many varieties of plants. I know this was not your question but just giving my example of not getting too technical and still getting good results. Link to comment Share on other sites More sharing options...
Piet Posted April 2, 2015 Author Report Share Posted April 2, 2015 Thanks for the responses and advice guys. The algae seems to have balanced out a little since when I posted this, and I managed to find two juvenile SAEs (smaller than the tetras) which are having a wonderful time with the algae! Might reduce the photoperiod slightly too, it's at 7 or 8 hours. I'll keep an eye on the CO2 input in response to the plants as they grow and keep testing the water chemistry. I'm guessing that I'm not injecting enough CO2 at the moment - didn't want to go too hard too fast - as I haven't noticed any noticeable change in pH from baseline. It's also a fairly high pH in my tank (need to retest this weekend) as I don't have a suitable soft, acidic water source... I was using some rainwater off the roof of the unit complex but then experienced a poisoning episode when using it 50/50 with tap water a few months ago - caught it quickly, did a 75% water change with tap water and didn't lose any fish, but they sure weren't looking too good! I live near the city on a fairly busy road and also near-ish to a freight transport railway... so there's probably all kinds of nasty chemical residues ending up in that water from the roof. I do appreciate that many people have great success with simpler setups, and I did as well when I was living with my parents where we had acidic, soft, nutrient rich non-contaminated rainwater. With the current setup I already had the T5HO lights for a while and decided that this would be the most successful course of action, after trying to increase plant growth with other methods. And I've wanted to experiment with high tech for a while now. I'll post some photos once things have balanced out a bit more. Cheers, Piet Link to comment Share on other sites More sharing options...
