700l labour of love

[KirstyF]

This tank has been a long time in the dreaming, but here and planted this weekend (mostly) so figured it was time to Journal.

Lots of firsts in this tank (was tempted to title this ‘the learning curve’ as I suspect this may be apt)
First Time for:
High Tec
Gyres for flow
DIY ferts
EI
At least 50% of the plants
Most of the kit I’m using
A tank big enough to have a bath in😂

So brace yourselves guys, I’m expecting to be posting lots of questions. 😊

Anyway, here’s the spec:
L84”, W24”, H22”
Optiwhite front and sides
Steel frame fully lidded cabinet
OA aquaria in Kidderminster did a fantastic job and their service is second to none.
2x Oase Biomaster Thermo 850’s (1550lph)
No issues with sucking air, burping or excessive noise, just a bit of a hum….so far 🤞
2x Maxspect Gyre FX330’s (9000lph) set up to create flow along the long axis of the tank.
Tested the filters with spraybars but couldn’t achieve a good circular flow so plumped for the gyres. Currently running both at 40% so I don’t blow the plants out of the soil. Got a little sway at the furthest point so we’ll see how they get on.
Co2Art pro elite regulator with additional manifold
2x Yidao in-line reactors - no mods (yet!)
1x59W and 1x46W Fluval Plant3 LED’s
These only make up a single strip so front to back coverage is currently not great but I blew my cash on the gyres so it’ll have to wait.

GH 12.6 (according to water report)
KH no idea - not on water report. An ancient dip test says about 6ish so….still no idea!!
PH - off gassed -7.2
Will be aiming at ph drop of 1unit by lights on. Co2 profiles in progress. 3hrs to get a 0.5 drop on this first attempt so a fair bit of tweaking still to do.
Tropica Aquasoil, sand, and bucket loads of lava rock underneath for height
DIY ferts - EI with an APFUK clone for micro’s
IFC calculator highly recommended, made DIY ferts so easy! 😊
Lights at 40% currently - 6hr photo period.
All plants are ‘low or medium’ light bar one and I’ve a fair few slow growers. Waiting on some more fast growers and floaters from lovely UKAPS folks and for AG to get some Albida Brown back in again. Need a little more moss and some more wood detailing too!

Any comments or suggestions on the above welcome.

And now the pics
Please ignore:
The plumbing debacle on the right (will get some more appropriate fittings once I’ve decided I’m happy with flow set-up)
The obvious gaps (they will get filled)
The lack of lid (I’ll put it on when the above is complete)
The appalling glueing in places (no excuse for that one😂)

 

[Geoffrey Rea]

Simply wow @KirstyF 😍

Your rock work alone is excellent and in such a large scape! Following 😉

 

[KirstyF]

Simply wow @KirstyF 😍

Your rock work alone is excellent and in such a large scape! Following 😉

Thank you so much.😊 My back may forgive me….eventually! 😂

 

[John q]

Not bad for a first attempt, but I bet you can't put a fruit pastel in your mouth without chewing it...

Only joking, tank looks fab.

 

[bazz]

Thank you so much.😊 My back may forgive me….eventually! 😂

Worth the pain, looks great!

 

[foxfish]

Great start, well done and good luck with your PH profiling.

 

[dw1305]

Hi all,

GH 12.6 (according to water report)
KH no idea - not on water report.

Carbonate hardness (dKH) will probably be about 12 - 13 as well for <"geological reasons">

Only joking, tank looks fab.

Certainly does.

cheers Darrel

 

[KirstyF]

Hi Darrel
Thanks for that. Always so helpful to have a science buff chip in. 😊
So….as mentioned above, new to Co2 injection but my understanding is that whilst a higher KH will buffer PH, the relationship between Co2 and PH sits outside of that so the 1 unit drop would indicate 30ppm of Co2 (or thereabouts) regardless. Is that correct?
Also, I believe most plants will still grow at this level of KH without issue? Anything in particular to avoid/think about?
And lastly, anything else I should be aware of or be considering based on this KH level?
Broad question I know but let’s run with it and see what comes up! 😊

Many thanks for your response.

 

[dw1305]

Hi all,

but my understanding is that whilst a higher KH will buffer PH, the relationship between Co2 and PH sits outside of that so the 1 unit drop would indicate 30ppm of Co2 (or thereabouts) regardless. Is that correct?

<"I think it is">.

science buff chip in

I don't really understand <"all the CO2 bits">.

Also, I believe most plants will still grow at this level of KH without issue? Anything in particular to avoid/think about?
And lastly, anything else I should be aware of or be considering based on this KH level?

I think most plants should be fine. @Geoffrey Rea or @Zeus. should be able to give you some "plants to grow" pointers. I might try @Roland as well as he uses low dKH water and may be able tell you plants that didn't do well in more carbonate rich water. Rotala rotundifolia looks a <"pretty good "canary"> for the iron (Fe) deficiencies etc. that are more likely to occur in harder water.

cheers Darrel

 

[KirstyF]

Also a ferts question.
It was my first micro dose today and when making up the solution I realised that I have (NH4)6Mo7024x4H20 rather than NaMo04,2H20. Not sure if I’ve been sent the wrong one or my ordering mistake. Ive left it out of the solution for now.
Any issue with using this and, if ok to use, any change in dosing quantity? or should I just leave and order the correct salt?

Many thanks

 

[KirstyF]

Hi all,

<"I think it is">.

I don't really understand <"all the CO2 bits">.

I think most plants should be fine. @Geoffrey Rea or @Zeus. should be able to give you some "plants to grow" pointers. I might try @Roland as well as he uses low dKH water and may be able tell you plants that didn't do well in more carbonate rich water. Rotala rotundifolia looks a <"pretty good "canary"> for the iron (Fe) deficiencies etc. that are more likely to occur in harder water.

cheers Darrel

Cheers Darrel
I’m using Fe 8% DTPA which I understand works better in harder water but I could certainly find a spot for that rotala. 👍

 

[Laoshan]

So….as mentioned above, new to Co2 injection but my understanding is that whilst a higher KH will buffer PH, the relationship between Co2 and PH sits outside of that so the 1 unit drop would indicate 30ppm of Co2 (or thereabouts) regardless.

I would say there is a relation between KH, pH and CO2 level, as per the classic table. Perhaps this is a good reference article?

The wrong way to read the pH/KH chart.

The pH/KH chart is often used to get a reading of CO2 levels in the tank. However, many folks go about this the wrong way. If you are estimating CO2 levels using only 1 pH reading - then chances are you are getting an incorrect estimation of CO2 levels. Read on to find out how to read pH/KH...

www.2hraquarist.com

Amazing scape BTW!

 

[KirstyF]

I would say there is a relation between KH, pH and CO2 level, as per the classic table. Perhaps this is a good reference article?

The wrong way to read the pH/KH chart.

The pH/KH chart is often used to get a reading of CO2 levels in the tank. However, many folks go about this the wrong way. If you are estimating CO2 levels using only 1 pH reading - then chances are you are getting an incorrect estimation of CO2 levels. Read on to find out how to read pH/KH...

www.2hraquarist.com

Amazing scape BTW!

Thank you @Laoshan 😊
I think this article almost answers the query.
I understand that if you have a low KH, PH can move more easily (in layman’s terms) and with a higher KH, PH can move less easily due to the buffering capacity of that KH (I’m not great on the science behind this) I was therefore not 100% sure whether having a high KH would impact the PH drop that is induced specifically by Co2 injection.
This article states (in short) that, with a KH between 1 and 10, you should just aim for the 1PH drop from your ‘normal’ level (de-gassed) in order to achieve the approximate 30ppm of Co2 as the charts don’t account for all variables.
I am therefore assuming that the 1 unit drop will result in approx 30ppm of Co2 regardless of what you start with, although interestingly it doesn’t mention whether a different method should be used if over 10KH, so I guess the question remains - is there a level of KH that would ‘interfere’ with achieving IRO 30ppm Co2 via a 1unit PH drop. i.e Can buffering capacity change this at some point?
I think ultimately the 1ph drop works (at least as a starting point) for most folks so I’m good with that. Just my head ticking over! 😊
Hope that makes sense!

 

[Laoshan]

It does make sense. I am not an expert here, just thinking along with you.

However, as KH represents the buffering capacity with regards to acidity, a higher KH means more acid is needed to lower pH a given amount. Therefore, much more than 30 ppm of CO2, acting as carbonic acid in the water, may be needed to lower pH by 1 at a KH of say 15, as is shown in the CO2 table. So you might be adding a bit too much CO2 when aiming for a 1 unit pH drop in water with a very high KH. Chemistry aside, it is always important to keep monitoring the fish and other critters while adjusting CO2, as I have learned the hard way…

 

[KirstyF]

---

Re-tested de-gassed water after 2 point calibration of PH pen and actual PH is 7.4.
Second attempt at Co2 and got to 6.5 at lights on but with gas on 4hrs before lights.
PH then stayed at 6.5 with just a couple of dips to 6.4 throughout photoperiod, so fairly stable.👍

4hrs seems a long time and I’m pumping a ton of gas to achieve this. A constant stream of bubbles through each of the two reactors (too many to count), so not very efficient at the mo. Might play with the inlet positions later but stable is good so happy for now.

I also noticed that as soon as the regulator kicked in, the working pressure dropped from its setting of 45psi to about 20psi and I had to adjust to get it back up. Anyone experienced a similar issue? Don’t want to have to be adjusting daily!

 

[dw1305]

Hi all,

I realised that I have (NH4)6Mo7024x4H20 rather than NaMo04,2H20. Not sure if I’ve been sent the wrong one or my ordering mistake. Ive left it out of the solution for now.
Any issue with using this and, if ok to use, any change in dosing quantity?

That is <"ammonium heptamolybdate tetrahydrate"> ((NH4)6Mo7O24.4H20), rather than (mono)sodium molybdate dihydrate (NaMoO4.2H2O).

You can use it, you are only interested in the molybdenum (Mo) content and it isn't actually <"that toxic to fish"> as a compound, even in doses many times higher than you are ever going to use.

To find out how much you would need to give you an equivalent dosing to the sodium molybdate you need to work out the Relative Molecular Mass (RMM) of each, and their percentage molybdenum, using the Relative Atomic Mass (RAM) of each element.

Because I do a bit of this sort of thing I have <"a spreadsheet with a periodic table embedded"> in it etc.

In this case there is quite a bit of adding up to do, but the RMM of ammonium molydate is 1236 and molybdenum has a RAM of 96. You have 7 molybdenum atoms which gives you 672 (7*96) and 672/1236 = 54% Mo for ammonium molybdate.

For sodium molybdate it is 44% molybdenum and 8.1 g of ammonium molybdate supplies as much Mo as 10 g of sodium molybdate.

cheers Darrel

 

[KirstyF]

Hi all,

That is <"ammonium heptamolybdate tetrahydrate"> ((NH4)6Mo7O24.4H20), rather than sodium molybdate dihydrate (NaMoO4.2H2O).

You can use it, you are only interested in the molybdenum (Mo) content and it isn't actually <"that toxic to fish"> as a compound, even in doses many times higher than you are ever going to use.

To find out how much you would need to give you an equivalent dosing to the sodium molybdate you need to work out the Relative Molecular Mass (RMM) of each, and their percentage molybdenum, using the Relative Atomic Mass (RAM) of each element.

Because I do a bit of this sort of thing I have <"a spreadsheet with a periodic table embedded"> in it etc.

In this case there is quite a bit of adding up to do, but the RMM of ammonium molydate is 1236 and molybdenum has a RAM of 96. You have 7 molybdenum atoms which gives you 672 (7*96) and 672/1236 = 54% Mo for ammonium molybdate.

For sodium molybdate it is 44% molybdenum and 8.1 g of ammonium molybdate supplies as much Mo as 10 g of sodium molybdate.

cheers Darrel

That’s fab and thank you for doing the math for me. Ur a star! 😊

 

[dw1305]

Hi all,

thank you for doing the math for me.

You are good, it doesn't take me long because I have a spreadsheet already set-up. If I had to start from scratch every time it would take a lot longer.

The <"Periodic table"> underlies all the <"nutrient calculators">, like our own <"IFC one"> etc. <"Microsoft have a template you can buy">, but there are plenty of free ones on the web (or you can type our own out).

In this case I had to look up the RAM for molybdenum (on the periodic table), because it isn't an element we use very frequently (it is used in the reagent for <"PO4--- testing">).

cheers Darrel

 

[Wolf6]

---

Re-tested de-gassed water after 2 point calibration of PH pen and actual PH is 7.4.
Second attempt at Co2 and got to 6.5 at lights on but with gas on 4hrs before lights.
PH then stayed at 6.5 with just a couple of dips to 6.4 throughout photoperiod, so fairly stable.👍

4hrs seems a long time and I’m pumping a ton of gas to achieve this. A constant stream of bubbles through each of the two reactors (too many to count), so not very efficient at the mo. Might play with the inlet positions later but stable is good so happy for now.

I also noticed that as soon as the regulator kicked in, the working pressure dropped from its setting of 45psi to about 20psi and I had to adjust to get it back up. Anyone experienced a similar issue? Don’t want to have to be adjusting daily!

My tank starts 4.5 hours before lights on and holds about 350liters. Only using a co2 bazooka under return pump inlet though so not the most efficiënt co2 diffusion, but anyways point is that it doesnt matter much if you have to start early provided you can keep it stable during lights on 🙂

 

[John q]

4hrs to reach a .9 drop probably isn't perfect Kirsty but that's how long it takes me to get a 1 point drop in a 240l tank. Like wolf points out getting it stable is the main thing, i can get it to drop quicker than 4hrs but then it continues to drop throughout the photo period.

@Zeus. Or @ceg4048 would be the best people to advise on this as they both have experience with large volume tanks.