# Co2 and low tech water changes



## leap (8 Sep 2015)

I just learned something new on another thread - why not to do water changes while the lights are on.
I'm so grateful for this forum, without which I don't think I could ever hope to even dream that I might have tanks that actually work out!

I've been struggling with some tanks of mine that are low tech in theory (except I have been dosing excel recently  in low doses to try to turn the decline around.)

I have plants that struggle - very little growth, yellow mottled leaves, diatom algae etc. I lowered my lighting times, put in a few root tabs, have been adding nutrients weekly and doing the excel in the mornings...

Added hornwort as a floater - within a week it is going yellow too & looks like it's melting...frogbit seems okay.

Also cleaned filters, done lots of siphoning out of organic matter & 10-20% w/c daily, with 50% weekly. I do w/c at night...with the lights on!

At first  things looked like they were turning around quite rapidly - less diatoms etc, but over the past few days the diatoms are back in force and although the plants do look a little better (a little greener & even a new leaf or two) they are far from healthy overall.

Anubias especially suffer - they had a white crusty film on them which I rubbed off...then diatoms, then started looking more perky - and now diatoms again...

So.........could it be the daily lights on w/changes that are untipping the balance in my tanks and making the plants miserable?

Maybe I just do too many water changes - but I read that lot's of small-ish changes are a good thing.

How long should I wait after turning off the lights before doing the w/changes?


----------



## ian_m (8 Sep 2015)

We need to know tank volume and lighting power and on time and carbon source if any and fertiliser source if any.

Though diatoms and your other plant issues all point towards too much light for too long and plants dying due to insufficient carbon source and/or fertiliser.


----------



## Jose (8 Sep 2015)

We dont know anything about your tank really. Would be good to know photoperiod, light intensity, what ferts you dose, and a photo.
You can do a wc right after lights are off.


----------



## MrAqua (8 Sep 2015)

How long have time have you had your tank(s) running? Are they established? I get a feeling that none of they are established yet..?


----------



## alto (8 Sep 2015)

leap said:


> Also cleaned filters, done lots of siphoning out of organic matter & 10-20% w/c daily, with 50% weekly. I do w/c at night...with the lights on!


I've seen this hypothesized on this forum but am very sceptical that water changes during the photoperiod has significant impact on most aquatic plants living the aquarium life  

I've never done water changes at any other time except with lights on ...  bit difficult to trim/vacuum suitably AND not syphon fish in the dark 

Re diatoms - do you have otocinclus in your tanks? they really are the stars of easy diatom control.

Water? hard, alkaline tap water used in tanks, or soft, acid tap water ...

Substrate? enriched (soil, addiitives etc) or plain sand/gravel

Livestock levels/type? some low tech setups depend on fish as CO2 source, waste from fish/fish food as plant nutrition etc, depending on your tap water parametres, this dependency may be the dominant factor (eg my tap water has negligible KH, GH, minimal macro & micro nutrients) or relatively minor factor.




leap said:


> Maybe I just do too many water changes


Not sure I believe that is possible  certainly fish appreciate optimum water quality ... I've yet to notice any plant depression post water change  

Plant sourcing can be a factor, make sure that plants are in excellent condition with good amounts of stored energy for the transition from emerse culture to submerse culture ... several local shops offer plants that are already declining (rapidly) in the dealer tanks


----------



## leap (8 Sep 2015)

Thanks everyone for help. I tried doing a w/c in the dark, in the wee am hours  and then had nightmares that maybe I had sucked up a shrimp or two...luckily this am they were still there pootering about.
I do the w/changes mainly for my fish - they seem to need it and like it.
A week ago I thought I was winning the battle - but with the return of the blessed diatoms I am not so sure now. What I find scary is how in a week things can change so fast....

I'll try to get some pics soon.

Here are the specs:

*24L tank:*
6 mnths old

*Filter:*
Eheim aquacompact 40

*Lights:*
Fugeray planted plus
7000k + (24) 660nm RED + (4) Blue Moonlights
8.9 Total Watts

Tanks are in a unit - lights are fixed on shelf above and hang about 14cm's above the water

Currently on 6 hours a day. Due to return of diatoms I have put an insect mesh screen between them & the tank - for a week now.

*Tap water:*
conditioned with prime
hard - very high GH
not tested in ages due to frequent w/c's & seachem ammonia alert on tanks - but last time it was tested ph was around 7.5

*Substrate:*
aquasoil, akadama and a little kyodama mix (leftovers from dabbling in bonsai!), bit of tropica concentrated that I had leftover , capped with sand to front , gravel to back

*Ferts:*
Seachem flourish root tabs 4 per tank & 2 broken up easy life clay ferts
3 drops excel daily, been at this for a month or so now.
Liquid Seachem Comprehensive once a week alternating with Easy life profito once a week
Just bought a small bottle of TNC complete to try out as not sure the 2 above are cutting the biscuit!

*Plants & condition of plants:*
Mainly anubias, moss, java, lotus, lily,sagittaria, crypts, hornwort, frogbit
a few scraggly stems of rotala (I think)

Anubias had white deposits on the leaves, I rubbed it off & since using excel this seems to have improved, no return of it yet...
Leaves are mottled yellow and don't look nice & glossy, but there are a few new leaves out.
Java has blackened transparent edges on some leaves

Hornwort has only been in quite recently - melting & yellow .... frogbit seems okay

*Fauna:*
1 Betta, 2 Amano shrimp & 2 nerites who poo a lot!


I would dearly LOVE some otto's ( sooooo tempted everytime I go to the LFS) but worry about there not being enough space in the tank for them?
Would keeping 3 little un's be cruel in a 24L?


----------



## Jose (8 Sep 2015)

One word: youre running out of ferts. Lack of ferts can cause algae. Dose NPK and micros. Maybe too much light also.


----------



## PARAGUAY (9 Sep 2015)

As I understand it your not using CO2 pressurised so the concensus is regular but less frequent smaller water changes weekly?as with the w/c regime you have maybe the levels of CO2 are fluctuating leaving ideal conditions for algae, I always waterchange ,maintain with the lights on but outside the normal lighting/CO2 photoperiod


----------



## leap (9 Sep 2015)

Yes, the consensus is regular small w/changes and no pressurised CO2.  Interesting your thoughts on CO2 fluctuating creating good conditions for algae Paraguay...it's a thought I have been having too.
Along with the possibility that each time I do these changes I am pulling nutrients out of the water. It's starting to look like at least part my problem is due to my meddling non stop which puts the balance into a constant flux - 
 But what to do? - my fish in particular seem to really benefit from the w/changes.
I will do maintenance & siphoning lights on,  then switch the lights off when I refill.

Jose - the ferts thing - do the ferts I use not contain enough nutrients?  I'm thinking of going EI route but want to use up all the ferts I have currently. Bottles of the stuff!  Could I maybe dose NPK along with the Profito/Seachem etc, or would that be overkill?


----------



## Jose (9 Sep 2015)

You can do the w. c. with your lights on no problem but outside the photoperiod and better after photoperiod or in the last minutes of it. Not good to do it before photoperiod unless its a few hours before so that excess co2 has time to gass off.


----------



## roadmaster (9 Sep 2015)

The flourish comprehensive has more micro nutrient's than macro nutrient's by content %, and although I have used it in NON CO2 tanks at twice weekly ,the plant's performed better for me with the addition of dry mineral salt's KNO3,KH2PO4,and K2SO4 and I used the flourish comprehensive as trace mineral source once a week till I ran out ,and purchased CSM+B to replace it.
I looked at daily dose for my size tank of Full EI,and dose this amount of all nutrient's once or twice a week ,with 50 % water change each week or maybe two week's.
I change water after light's off for the day and wrapped suction hose with mesh to keep from sucking up Amano shrimp,cherry shrimp.and small tetra's.
I use no CO2 or excel so lighting is subdued and on straight eight hour photo period.


----------



## ian_m (9 Sep 2015)

Jose said:


> Not good to do it before photoperiod unless its a few hours before so that excess co2 has time to gass off.


Err no. CO2 level doesn't matter if the lights are off. So changing water and tank fiddling are fine before lights on, CO2 level of added water is irrelevant if light are off.


----------



## Jose (9 Sep 2015)

ian_m said:


> Err no. CO2 level doesn't matter if the lights are off. So changing water and tank fiddling are fine before lights on, CO2 level of added water is irrelevant if light are off.



What about if you do it right before lights on? CO2 levels will peak right before photosynthesis starts and will then drop off. Bad thing.


----------



## ian_m (9 Sep 2015)

Jose said:


> CO2 levels will peak right before photosynthesis starts and will then drop off. Bad thing


Probably not. Unless you are injecting CO2 the excess CO2 from water change will most likely gas off in minutes especially as if you are fiddling with the tank. When I have...sorry a friend of mine ...has accidentally gassed his fish with a beyond yellow drop checker, putting an air stone on restores normal fish behaviour from surface gasping to food searching in literally minutes.

I have changed my water when convenient for me, so this covers all times, in morning usually, lunch time before CO2 on, had CO2 come on whilst fiddling and filter was off during maintenance (giant gas burp in diffuser when turned on), changed water mid way through lights on and quite often water changes at 7-8 pm in evening towards and of CO2 time. Not noticed any tank differences. I think the presence of fresh water overrides any possible CO2 issues.


----------



## Jose (9 Sep 2015)

ian_m said:


> I have changed my water when convenient for me, so this covers all times, in morning usually, lunch time before CO2 on, had CO2 come on whilst fiddling and filter was off during maintenance (giant gas burp in diffuser when turned on), changed water mid way through lights on and quite often water changes at 7-8 pm in evening towards and of CO2 time. Not noticed any tank differences. I think the presence of fresh water overrides any possible CO2 issues.



As I said at the start, its just a safe measure. Not every tap water has the same co2 levels.Does not apply if injecting co2 like i suppose you are. Only for nn co2 tanks. Its a theory thats all. It costs nothing to do right.


----------



## roadmaster (9 Sep 2015)

I HAVE noticed difference when changing water with light's on, hence why I change the water at night with just lamp on other side of the room to give me enough light to see what I'm doing.(How much light does one need to drain half the water from a glass box?)
I believe there is enough fluctuation in CO2 from the tap  to my NON CO2 tank's from large 50% water changes, that I sometimes see hair algae on tops of plant's closer to the surface where light is stronger and CO2 is a bit higher.
If I perform the water changes at night,,I do not have the hair algae.(lot's of  observing this  with four different tanks)
Have also noted that I can simply not perform a water change for three or four week's and BBA,hair algae, seem to go away nearly as suddenly as they appeared.
Maybeso, I'm completely mistaken with my purely unscientific observations but is enough for me .


----------



## Tim Harrison (9 Sep 2015)

I don't subscribe to the whole CO2 water changes thingy http://www.ukaps.org/forum/threads/co2-in-tapwater.29637/#post-309953


----------



## ltsai (9 Sep 2015)

I turned on lights to change, otherwise cant vacuum and clean the glasd cleanly, but before or after co2. 

Sent from my Mi 4i using Tapatalk


----------



## foxfish (9 Sep 2015)




----------



## ian_m (9 Sep 2015)

Actually reading the title of this thread again, this is low tech tank with low light so CO2 levels from incoming water will make b**ger all difference, plants won't be "overloaded" as light is low. The CO2 will probably get dissipated very quickly with all the tank faffing anyway.

So low tech tank change water when ever you like. Light doesn't matter.


----------

