# Relationship between EI Dosing & TDS on the Fertilisation and Hatching rate of Discus eggs



## REDSTEVEO (1 Dec 2015)

Hi All,

Those of you who have seen the latest update on my journal 'The Full Monty' will know that I bit the bullet and sold the remaining two male discus I had in my tank. You will have also seen recently the photographs of the proven pair of Super Red Flame Discus in my aquarium. 

They have only been in a week and on Saturday night at 8.30pm they spawned around 200 eggs in a nice cluster. The TDS when I put them in was around 300. After a few partial water changes I managed to get the TDS down to just under 200. After 36 hours most of the eggs were still okay with no mould or fungus on them, after 48 hours about 60% had the white fungus on them. This morning after at the 60 hours point there are around 20 maybe 30 wrigglers on the pot, the parents are looking after them at the moment.

I believe that the high TDS has an adverse effect on the fertilisation process and on the hatching rate. My problem is if I do water changes to lower the TDS and don't add any plant fertilisers (EI or otherwise) some of the plants begin to melt and I also get an outbreak of BGA. So I am torn between getting a good fertilisation and hatching rate at the expense of the plants. My tap water has a very low GH and KH and if I don't add KH and GH buffers the plants also start to suffer, but the buffers combined with the fertilisers also raise the TDS levels to around 350 TDS. This is definitely too high for discus to get a proper fertilisation and good hatching rate.

A bit of a dilemma, so I wondered whether anyone has any thoughts or had any advice or suggestions on how to get the TDS down and keep the plants healthy. Its a bit of a juggling act at the moment.

I have consulted with Clive 'The Wise One' for his opinions as he is a bit of a Guru on the subject of EI, but all help or advice will be much appreciated.

Cheers,

Steve


----------



## REDSTEVEO (1 Dec 2015)

Just reading this article now, hmmm...

http://ukaps.org/forum/threads/ei-dosing-impact-on-fish-breeding-and-fry.17024/

Steve


----------



## REDSTEVEO (4 Dec 2015)

Right I have been trying to do some calculations around TDS and the additives that we pour into our tank. So I have done some experiments. Starting with a TDS in the tank of 320 I wanted to see which chemicals / additives were driving up the TDS the most.

I worked with 400 mls of water in a glass from two different sources and added 5 mls of each of my additives to separate glasses. Here are the results.

Test Medium
400 mls of tap water in a glass measuring 100 TDS
400 mls of HMA water in a glass measuring 100 TDS

Additives 
5ml EI Mixture   = 172 TDS (increase of 72)
5ml CSM +        =  245 TDS (increase of 145)
5ml Tropica Specialised Fertiliser = 854 (increase of 754)
5ml Easy Carbo = 101 TDS (increase of 1)
5ml Easy Ferro = 230 TDS (increase of 130)
5ml of KH Plus = 686 TDS (increase of 586)
5ml ADA Green Brighty Step 3 = 183 TDS (increase of 83)

So from the results above those with the highest impact on TDS are the Tropica Specialised Fertiliser and the KH Plus.

Now all I need is plantbrain or someone who is really good at mathematics to work out what the calculations would be if 5ml of these was added to 100 or 400 litres of water.

I have done 5 very slow water changes in succession all in one day recently of around 60 litres at a time with water coming at a slow trickle from my HMA Filter. By doing this I managed to keep the temperature at a steady 29 degrees. I filled up the tank, then drained off another 60 litres and repeated five times, this was over the course of a whole day. This has reduced the TDS from 320 down to 200. If I do the same again in a day or two, hopefully this will bring it down to around 120 ish before the discus spawn again in a few days time.

Now I just need to measure the KH and GH and work out if my plants are going melt on me.

I hope you found these facts useful. Any thoughts or views please let me know.

Cheers,

Steve


----------



## Mick.Dk (6 Dec 2015)

Hi Steve - interesting/puzzling "problematics"......
Without too much comparison, I had same "problematics" a long time ago, when I first started to breed angel-fish. At that time most "strains" og angels were far less domesticated, than they are now. This called for special conditions of water too, especially for breeding.
To be honest, I chose to go the other way around it: I happily accepted very low percentages of hatching and very few fish growing adult. I concentrated on those few adults (cross-bred from different parents, ofcourse) to establish strains tolerating my water. Later I deliberately stopped using anti-fungal acessories, starting from low percentage of survivors too. Finally I inbreed those fish to other colour-strains. Today I have 80-90 percent hatching !!
Point is; you can focus on changing water parametres OR you can focus on "toughen up" your fish, genetically. A combination is ofcorse possible, too.
As far as I know, this is what the german "Denker discus" guys have done.............
Just a thought........


----------



## REDSTEVEO (8 Dec 2015)

Thanks Mick,

The discus spawned again early yesterday morning with a TDS of 185. I was about to do another water change to bring the TDS down to below 150 but decided it was too late, the eggs had been laid so no point in changing water now. The eggs still look quite good so i will see how they get on this time. I agree with what you say about adapting fish to the water conditions and not the other way around. Trouble is I will probably never take it to that level of cross breeding.

I'll keep you posted.

Steve


----------



## Manu (8 Dec 2015)

Hi Steve,
I've got no idea about keeping discus but this my logical thought:
If you don't want to add too much ferts to keep tds low, what about reducing the lights for a while until the eggs hatch? Less light means less ferts, and less risk of BGA and melt.
I might be wrong.
Anyway, I hope you're successful with your discus 

Cheers, 
Manu 

Sent from my D5803 using Tapatalk


----------



## REDSTEVEO (13 Dec 2015)

Hi Manu,
You are partly right in what you say. Strangely enough when the discus have spawned, I have left the LED light on at a low light setting for over 72 hours. This is so the discus can see their eggs and fan them continuously until they hatch. Oddly there has been no algae outbreak, no BGA and no plant melt down. This is despite the fact that I have got the TDS down to below 150 TDS. I have only used remineralised RO water and added no fertilisers whatsoever.

Cheers,

Steve


----------

